From 1d86a0f4707f9de493f0d78e1ee34991652d0b82 Mon Sep 17 00:00:00 2001
From: legendecas <legendecas@gmail.com>
Date: Thu, 18 Aug 2022 00:46:14 +0800
Subject: [PATCH] perf_hooks: fix webperf idlharness

1. Enforce receiver checks on IDL interfaces.
2. Avoid prototype manipulation on constructing IDL interfaces with
   `ReflectConstruct`.
3. `defineReplaceableAttribute` should create IDL getter/setter.
4. Event handler properties defined by `defineEventHandler` should check
   if the receiver is a valid `EventTarget`.
5. Corrected `PerformanceResourceTiming` to inherit the public interface
   `PerformanceEntry` instead of the internal interface
   `InternalPerformanceResourceTiming`.
---
 doc/api/perf_hooks.md                         | 153 ++++++
 lib/internal/bootstrap/browser.js             |  31 +-
 lib/internal/event_target.js                  |  65 ++-
 lib/internal/perf/observe.js                  |  79 ++-
 lib/internal/perf/performance.js              | 246 ++++-----
 lib/internal/perf/performance_entry.js        | 107 +++-
 lib/internal/perf/resource_timing.js          |  96 +++-
 lib/internal/perf/timerify.js                 |   4 +-
 lib/internal/perf/usertiming.js               |  69 ++-
 lib/internal/perf/utils.js                    |   2 +-
 lib/internal/process/pre_execution.js         |   1 -
 lib/internal/validators.js                    |   9 +-
 test/common/wpt.js                            |  49 +-
 test/fixtures/wpt/README.md                   |   3 +-
 test/fixtures/wpt/interfaces/WebCryptoAPI.idl |   3 +-
 test/fixtures/wpt/interfaces/console.idl      |   2 +-
 test/fixtures/wpt/interfaces/dom.idl          |  19 +-
 test/fixtures/wpt/interfaces/encoding.idl     |   8 +-
 test/fixtures/wpt/interfaces/hr-time.idl      |   4 +-
 test/fixtures/wpt/interfaces/html.idl         | 228 ++++----
 .../wpt/interfaces/performance-timeline.idl   |   6 +-
 .../wpt/interfaces/resource-timing.idl        |  32 ++
 test/fixtures/wpt/interfaces/streams.idl      |  44 +-
 test/fixtures/wpt/interfaces/url.idl          |   4 +-
 test/fixtures/wpt/interfaces/user-timing.idl  |   4 +-
 test/fixtures/wpt/interfaces/webidl.idl       |  50 ++
 .../304-response-recorded.html                |  53 ++
 .../wpt/resource-timing/CodingConventions.md  |  77 +++
 test/fixtures/wpt/resource-timing/META.yml    |   6 +
 .../SO-XO-SO-redirect-chain-tao.https.html    |  64 +++
 .../wpt/resource-timing/TAO-match.html        |  82 +++
 .../TAO-port-mismatch-means-crossorigin.html  |  46 ++
 .../buffer-full-add-after-full-event.html     |  27 +
 ...add-entries-during-callback-that-drop.html |  29 +
 ...ffer-full-add-entries-during-callback.html |  28 +
 .../buffer-full-add-then-clear.html           |  31 ++
 ...-full-decrease-buffer-during-callback.html |  26 +
 .../buffer-full-eventually.html               |  31 ++
 ...-full-increase-buffer-during-callback.html |  26 +
 ...r-full-inspect-buffer-during-callback.html |  30 +
 .../buffer-full-set-to-current-buffer.html    |  34 ++
 ...-full-store-and-clear-during-callback.html |  36 ++
 .../buffer-full-then-decreased.html           |  29 +
 .../buffer-full-then-increased.html           |  28 +
 .../buffer-full-when-populate-entries.html    |  30 +
 .../wpt/resource-timing/buffered-flag.any.js  |  18 +
 .../cached-image-gets-single-entry.html       |  67 +++
 .../clear-resource-timings.html               |  22 +
 .../wpt/resource-timing/connection-reuse.html |  56 ++
 .../connection-reuse.https.html               |  25 +
 .../wpt/resource-timing/cors-preflight.any.js |  49 ++
 .../resource-timing/cross-origin-iframe.html  |  33 ++
 .../cross-origin-redirects.html               | 102 ++++
 ...-origin-start-end-time-with-redirects.html |  32 ++
 .../cross-origin-status-codes.html            |  70 +++
 .../document-domain-no-impact-opener.html     |  16 +
 .../entries-for-network-errors.sub.https.html |  35 ++
 .../wpt/resource-timing/entry-attributes.html |  39 ++
 .../resource-timing/event-source-timing.html  |  32 ++
 .../fetch-cross-origin-redirect.https.html    |  33 ++
 .../wpt/resource-timing/font-timestamps.html  |  62 +++
 .../wpt/resource-timing/frameset-timing.html  |   6 +
 .../wpt/resource-timing/idlharness.any.js     |  24 +
 .../resource-timing/iframe-failed-commit.html | 108 ++++
 .../wpt/resource-timing/iframe-non-html.html  |  23 +
 .../iframe-redirect-without-location.html     |  17 +
 .../iframe-sequence-of-events.html            |  12 +
 .../resource-timing/iframe-with-download.html |  24 +
 .../image-sequence-of-events.html             |  29 +
 .../initiator-type-for-script.html            |  67 +++
 .../resource-timing/initiator-type/audio.html |  34 ++
 .../initiator-type/dynamic-insertion.html     |  41 ++
 .../resource-timing/initiator-type/embed.html |  20 +
 .../initiator-type/frameset.html              |  22 +
 .../initiator-type/iframe.html                |  19 +
 .../initiator-type/img-srcset.html            |  21 +
 .../resource-timing/initiator-type/img.html   |  19 +
 .../resource-timing/initiator-type/input.html |  19 +
 .../resource-timing/initiator-type/link.html  |  38 ++
 .../resource-timing/initiator-type/misc.html  |  31 ++
 .../initiator-type/picture.html               |  39 ++
 .../resources/initiator-type-test.js          |  15 +
 .../initiator-type/script.html                |  26 +
 .../resource-timing/initiator-type/style.html |  45 ++
 .../resource-timing/initiator-type/svg.html   |  23 +
 .../resource-timing/initiator-type/video.html |  32 ++
 .../initiator-type/workers.html               |  23 +
 .../input-sequence-of-events.html             |  21 +
 .../link-sequence-of-events.html              |  30 +
 .../load-from-mem-cache-transfer-size.html    |  65 +++
 .../nested-context-navigations-embed.html     |  36 ++
 .../nested-context-navigations-iframe.html    |  32 ++
 .../nested-context-navigations-object.html    |  37 ++
 ...extHopProtocol-is-tao-protected.https.html |  49 ++
 ...ries-for-cross-origin-css-fetched.sub.html |  39 ++
 .../object-not-found-adds-entry.html          |  37 ++
 ...found-after-TAO-cross-origin-redirect.html |  47 ++
 ...not-found-after-cross-origin-redirect.html |  35 ++
 .../wpt/resource-timing/opaque-origin.html    |  46 ++
 .../wpt/resource-timing/ping-rt-entries.html  |  29 +
 .../wpt/resource-timing/redirects.html        |  61 +++
 .../render-blocking-status-link.html          | 222 ++++++++
 .../render-blocking-status-script.html        | 196 +++++++
 .../resource-ignore-data-url.html             |  39 ++
 .../resource-timing/resource-reload-TAO.html  |  18 +
 .../resource-timing/resource-timing-level1.js | 517 ++++++++++++++++++
 .../resource-timing-level1.sub.html           |  19 +
 ...source_connection_reuse_mixed_content.html |  55 ++
 ...nnection_reuse_mixed_content_redirect.html |  55 ++
 .../resource_dedicated_worker.html            |  28 +
 ...resource_nested_dedicated_worker.worker.js |  17 +
 .../resource-timing/resource_reparenting.html |  53 ++
 .../resource_subframe_self_navigation.html    |  53 ++
 .../resource-timing/resource_timing.worker.js |  64 +++
 .../resource_timing_content_length.html       |  35 ++
 .../resource-timing/resources/200.https.asis  |   5 +
 .../resource-timing/resources/200_empty.asis  |   3 +
 .../resource-timing/resources/204_empty.asis  |   3 +
 .../resource-timing/resources/205_empty.asis  |   3 +
 .../resources/blank-with-tao.html             |  10 +
 .../resources/blank-with-tao.html.headers     |   1 +
 .../resources/blue-with-tao.png               | Bin 0 -> 1010 bytes
 .../resources/blue-with-tao.png.headers       |   1 +
 .../wpt/resource-timing/resources/blue.png    | Bin 0 -> 1010 bytes
 .../resources/buffer-full-utilities.js        |  75 +++
 .../wpt/resource-timing/resources/close.html  |   1 +
 .../resources/connection-reuse-test.js        |  63 +++
 .../resources/csp-default-none.html           |   3 +
 .../resources/csp-default-none.html.headers   |   2 +
 .../resources/document-domain-no-impact.html  |  28 +
 .../resources/document-navigated.html         |  12 +
 .../resources/document-refreshed.html         |  12 +
 .../resources/document-that-navigates.html    |  11 +
 .../resources/document-that-refreshes.html    |   9 +
 .../resource-timing/resources/download.asis   |   6 +
 .../resources/embed-navigate-back.html        |  18 +
 .../resources/embed-navigate.html             |  18 +
 .../resources/embed-refresh.html              |  18 +
 .../wpt/resource-timing/resources/empty.js    |   1 +
 .../resource-timing/resources/empty_script.js |   0
 .../resource-timing/resources/empty_style.css |   1 +
 .../resources/entry-invariants.js             | 507 +++++++++++++++++
 .../resources/fake_responses.html             |  19 +
 .../resources/fake_responses_https.sub.html   |  18 +
 .../fake_responses_https_redirect.sub.html    |  20 +
 .../resource-timing/resources/frame-timing.js |  48 ++
 .../resources/frameset-timing-frame.html      |   8 +
 .../resources/green-frame.html                |   7 +
 .../wpt/resource-timing/resources/green.html  |  10 +
 .../resources/green.html.headers              |   1 +
 .../iframe-TAO-crossorigin-port.sub.html      |  31 ++
 ...ame-load-from-mem-cache-transfer-size.html |  24 +
 .../resources/iframe-navigate-back.html       |  18 +
 .../resources/iframe-navigate.html            |  18 +
 .../resources/iframe-refresh.html             |  18 +
 .../resources/iframe-reload-TAO.html          |  25 +
 .../resources/iframe-setdomain.sub.html       |  14 +
 .../resources/iframe-with-delay.sub.html      |   3 +
 .../resources/iframe_TAO_match_origin.html    |  21 +
 .../resource-timing/resources/import.sub.css  |   1 +
 .../resource-timing/resources/importer.css    |   1 +
 .../wpt/resource-timing/resources/importer.js |   2 +
 .../resources/importer_async.js               |   2 +
 .../resources/importer_dynamic.css            |   1 +
 .../resources/importer_print.css              |   1 +
 .../resources/inject_resource_test.html       |   7 +
 .../wpt/resource-timing/resources/invalid.jpg |   1 +
 .../resource-timing/resources/manifest.json   |   4 +
 .../resources/navigate_back.html              |   7 +
 .../resources/nested-contexts.js              | 110 ++++
 .../wpt/resource-timing/resources/nested.css  |  10 +
 .../resources/notify_parent.html              |   4 +
 .../resources/object-navigate-back.html       |  18 +
 .../resources/object-navigate.html            |  18 +
 .../resources/object-refresh.html             |  18 +
 .../resources/observe-entry.js                |  25 +
 .../resources/resource-loaders.js             | 133 +++++
 .../resources/resource_timing_test0.css       |   4 +
 .../resources/resource_timing_test0.html      |  15 +
 .../resources/resource_timing_test0.js        |   3 +
 .../resource_timing_test0.js.headers          |   2 +
 .../resources/resource_timing_test0.png       | Bin 0 -> 249 bytes
 .../resources/resource_timing_test0.xml       |   6 +
 .../resources/self_navigation.html            |   1 +
 .../resources/shared-worker.js                |   3 +
 .../resource-timing/resources/sizes-helper.js |  16 +
 .../resource-timing/resources/sw-install.html |  58 ++
 .../wpt/resource-timing/resources/sw.js       |   3 +
 .../resource-timing/resources/tao-response.js |  13 +
 .../resources/webperftestharness.js           | 166 ++++++
 .../resources/webperftestharnessextension.js  | 188 +++++++
 .../resources/worker_with_images.js           |  22 +
 ...ame-origin-from-cross-origin-redirect.html |  31 ++
 .../resource-timing/script-rt-entries.html    |  37 ++
 .../secure-iframe-in-insecure-context.html    |  32 ++
 .../shared-worker-rt-entry.html               |  26 +
 .../wpt/resource-timing/sizes-cache.any.js    |  55 ++
 .../resource-timing/sizes-redirect-img.html   |  57 ++
 .../wpt/resource-timing/sizes-redirect.any.js |  62 +++
 .../status-codes-create-entry.html            |  40 ++
 .../supported_resource_type.any.js            |  24 +
 .../resource-timing/test_resource_timing.html |  24 +
 .../test_resource_timing.https.html           |  24 +
 .../resource-timing/test_resource_timing.js   | 228 ++++++++
 test/fixtures/wpt/resource-timing/tojson.html |  69 +++
 .../workerStart-tao-protected.https.html      |  76 +++
 .../worklet-rt-entries.https.html             |  19 +
 .../resource-timing/xhr-resource-timing.html  |  29 +
 test/fixtures/wpt/versions.json               |   6 +-
 .../test-perf-hooks-resourcetiming.js         |  25 +-
 test/parallel/test-perf-hooks-usertiming.js   |  62 +--
 test/sequential/test-worker-eventlooputil.js  |   7 +-
 test/wpt/status/hr-time.json                  |   3 -
 test/wpt/status/performance-timeline.json     |   6 +-
 test/wpt/status/resource-timing.json          |  23 +
 test/wpt/status/user-timing.json              |   3 -
 test/wpt/test-hr-time.js                      |   9 +-
 test/wpt/test-performance-timeline.js         |  58 +-
 test/wpt/test-resource-timing.js              |  48 ++
 test/wpt/test-user-timing.js                  |  40 +-
 220 files changed, 8022 insertions(+), 512 deletions(-)
 create mode 100644 test/fixtures/wpt/interfaces/resource-timing.idl
 create mode 100644 test/fixtures/wpt/interfaces/webidl.idl
 create mode 100644 test/fixtures/wpt/resource-timing/304-response-recorded.html
 create mode 100644 test/fixtures/wpt/resource-timing/CodingConventions.md
 create mode 100644 test/fixtures/wpt/resource-timing/META.yml
 create mode 100644 test/fixtures/wpt/resource-timing/SO-XO-SO-redirect-chain-tao.https.html
 create mode 100644 test/fixtures/wpt/resource-timing/TAO-match.html
 create mode 100644 test/fixtures/wpt/resource-timing/TAO-port-mismatch-means-crossorigin.html
 create mode 100644 test/fixtures/wpt/resource-timing/buffer-full-add-after-full-event.html
 create mode 100644 test/fixtures/wpt/resource-timing/buffer-full-add-entries-during-callback-that-drop.html
 create mode 100644 test/fixtures/wpt/resource-timing/buffer-full-add-entries-during-callback.html
 create mode 100644 test/fixtures/wpt/resource-timing/buffer-full-add-then-clear.html
 create mode 100644 test/fixtures/wpt/resource-timing/buffer-full-decrease-buffer-during-callback.html
 create mode 100644 test/fixtures/wpt/resource-timing/buffer-full-eventually.html
 create mode 100644 test/fixtures/wpt/resource-timing/buffer-full-increase-buffer-during-callback.html
 create mode 100644 test/fixtures/wpt/resource-timing/buffer-full-inspect-buffer-during-callback.html
 create mode 100644 test/fixtures/wpt/resource-timing/buffer-full-set-to-current-buffer.html
 create mode 100644 test/fixtures/wpt/resource-timing/buffer-full-store-and-clear-during-callback.html
 create mode 100644 test/fixtures/wpt/resource-timing/buffer-full-then-decreased.html
 create mode 100644 test/fixtures/wpt/resource-timing/buffer-full-then-increased.html
 create mode 100644 test/fixtures/wpt/resource-timing/buffer-full-when-populate-entries.html
 create mode 100644 test/fixtures/wpt/resource-timing/buffered-flag.any.js
 create mode 100644 test/fixtures/wpt/resource-timing/cached-image-gets-single-entry.html
 create mode 100644 test/fixtures/wpt/resource-timing/clear-resource-timings.html
 create mode 100644 test/fixtures/wpt/resource-timing/connection-reuse.html
 create mode 100644 test/fixtures/wpt/resource-timing/connection-reuse.https.html
 create mode 100644 test/fixtures/wpt/resource-timing/cors-preflight.any.js
 create mode 100644 test/fixtures/wpt/resource-timing/cross-origin-iframe.html
 create mode 100644 test/fixtures/wpt/resource-timing/cross-origin-redirects.html
 create mode 100644 test/fixtures/wpt/resource-timing/cross-origin-start-end-time-with-redirects.html
 create mode 100644 test/fixtures/wpt/resource-timing/cross-origin-status-codes.html
 create mode 100644 test/fixtures/wpt/resource-timing/document-domain-no-impact-opener.html
 create mode 100644 test/fixtures/wpt/resource-timing/entries-for-network-errors.sub.https.html
 create mode 100644 test/fixtures/wpt/resource-timing/entry-attributes.html
 create mode 100644 test/fixtures/wpt/resource-timing/event-source-timing.html
 create mode 100644 test/fixtures/wpt/resource-timing/fetch-cross-origin-redirect.https.html
 create mode 100644 test/fixtures/wpt/resource-timing/font-timestamps.html
 create mode 100644 test/fixtures/wpt/resource-timing/frameset-timing.html
 create mode 100644 test/fixtures/wpt/resource-timing/idlharness.any.js
 create mode 100644 test/fixtures/wpt/resource-timing/iframe-failed-commit.html
 create mode 100644 test/fixtures/wpt/resource-timing/iframe-non-html.html
 create mode 100644 test/fixtures/wpt/resource-timing/iframe-redirect-without-location.html
 create mode 100644 test/fixtures/wpt/resource-timing/iframe-sequence-of-events.html
 create mode 100644 test/fixtures/wpt/resource-timing/iframe-with-download.html
 create mode 100644 test/fixtures/wpt/resource-timing/image-sequence-of-events.html
 create mode 100644 test/fixtures/wpt/resource-timing/initiator-type-for-script.html
 create mode 100644 test/fixtures/wpt/resource-timing/initiator-type/audio.html
 create mode 100644 test/fixtures/wpt/resource-timing/initiator-type/dynamic-insertion.html
 create mode 100644 test/fixtures/wpt/resource-timing/initiator-type/embed.html
 create mode 100644 test/fixtures/wpt/resource-timing/initiator-type/frameset.html
 create mode 100644 test/fixtures/wpt/resource-timing/initiator-type/iframe.html
 create mode 100644 test/fixtures/wpt/resource-timing/initiator-type/img-srcset.html
 create mode 100644 test/fixtures/wpt/resource-timing/initiator-type/img.html
 create mode 100644 test/fixtures/wpt/resource-timing/initiator-type/input.html
 create mode 100644 test/fixtures/wpt/resource-timing/initiator-type/link.html
 create mode 100644 test/fixtures/wpt/resource-timing/initiator-type/misc.html
 create mode 100644 test/fixtures/wpt/resource-timing/initiator-type/picture.html
 create mode 100644 test/fixtures/wpt/resource-timing/initiator-type/resources/initiator-type-test.js
 create mode 100644 test/fixtures/wpt/resource-timing/initiator-type/script.html
 create mode 100644 test/fixtures/wpt/resource-timing/initiator-type/style.html
 create mode 100644 test/fixtures/wpt/resource-timing/initiator-type/svg.html
 create mode 100644 test/fixtures/wpt/resource-timing/initiator-type/video.html
 create mode 100644 test/fixtures/wpt/resource-timing/initiator-type/workers.html
 create mode 100644 test/fixtures/wpt/resource-timing/input-sequence-of-events.html
 create mode 100644 test/fixtures/wpt/resource-timing/link-sequence-of-events.html
 create mode 100644 test/fixtures/wpt/resource-timing/load-from-mem-cache-transfer-size.html
 create mode 100644 test/fixtures/wpt/resource-timing/nested-context-navigations-embed.html
 create mode 100644 test/fixtures/wpt/resource-timing/nested-context-navigations-iframe.html
 create mode 100644 test/fixtures/wpt/resource-timing/nested-context-navigations-object.html
 create mode 100644 test/fixtures/wpt/resource-timing/nextHopProtocol-is-tao-protected.https.html
 create mode 100644 test/fixtures/wpt/resource-timing/no-entries-for-cross-origin-css-fetched.sub.html
 create mode 100644 test/fixtures/wpt/resource-timing/object-not-found-adds-entry.html
 create mode 100644 test/fixtures/wpt/resource-timing/object-not-found-after-TAO-cross-origin-redirect.html
 create mode 100644 test/fixtures/wpt/resource-timing/object-not-found-after-cross-origin-redirect.html
 create mode 100644 test/fixtures/wpt/resource-timing/opaque-origin.html
 create mode 100644 test/fixtures/wpt/resource-timing/ping-rt-entries.html
 create mode 100644 test/fixtures/wpt/resource-timing/redirects.html
 create mode 100644 test/fixtures/wpt/resource-timing/render-blocking-status-link.html
 create mode 100644 test/fixtures/wpt/resource-timing/render-blocking-status-script.html
 create mode 100644 test/fixtures/wpt/resource-timing/resource-ignore-data-url.html
 create mode 100644 test/fixtures/wpt/resource-timing/resource-reload-TAO.html
 create mode 100644 test/fixtures/wpt/resource-timing/resource-timing-level1.js
 create mode 100644 test/fixtures/wpt/resource-timing/resource-timing-level1.sub.html
 create mode 100644 test/fixtures/wpt/resource-timing/resource_connection_reuse_mixed_content.html
 create mode 100644 test/fixtures/wpt/resource-timing/resource_connection_reuse_mixed_content_redirect.html
 create mode 100644 test/fixtures/wpt/resource-timing/resource_dedicated_worker.html
 create mode 100644 test/fixtures/wpt/resource-timing/resource_nested_dedicated_worker.worker.js
 create mode 100644 test/fixtures/wpt/resource-timing/resource_reparenting.html
 create mode 100644 test/fixtures/wpt/resource-timing/resource_subframe_self_navigation.html
 create mode 100644 test/fixtures/wpt/resource-timing/resource_timing.worker.js
 create mode 100644 test/fixtures/wpt/resource-timing/resource_timing_content_length.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/200.https.asis
 create mode 100644 test/fixtures/wpt/resource-timing/resources/200_empty.asis
 create mode 100644 test/fixtures/wpt/resource-timing/resources/204_empty.asis
 create mode 100644 test/fixtures/wpt/resource-timing/resources/205_empty.asis
 create mode 100644 test/fixtures/wpt/resource-timing/resources/blank-with-tao.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/blank-with-tao.html.headers
 create mode 100644 test/fixtures/wpt/resource-timing/resources/blue-with-tao.png
 create mode 100644 test/fixtures/wpt/resource-timing/resources/blue-with-tao.png.headers
 create mode 100644 test/fixtures/wpt/resource-timing/resources/blue.png
 create mode 100644 test/fixtures/wpt/resource-timing/resources/buffer-full-utilities.js
 create mode 100644 test/fixtures/wpt/resource-timing/resources/close.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/connection-reuse-test.js
 create mode 100644 test/fixtures/wpt/resource-timing/resources/csp-default-none.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/csp-default-none.html.headers
 create mode 100644 test/fixtures/wpt/resource-timing/resources/document-domain-no-impact.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/document-navigated.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/document-refreshed.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/document-that-navigates.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/document-that-refreshes.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/download.asis
 create mode 100644 test/fixtures/wpt/resource-timing/resources/embed-navigate-back.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/embed-navigate.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/embed-refresh.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/empty.js
 create mode 100644 test/fixtures/wpt/resource-timing/resources/empty_script.js
 create mode 100644 test/fixtures/wpt/resource-timing/resources/empty_style.css
 create mode 100644 test/fixtures/wpt/resource-timing/resources/entry-invariants.js
 create mode 100644 test/fixtures/wpt/resource-timing/resources/fake_responses.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/fake_responses_https.sub.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/fake_responses_https_redirect.sub.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/frame-timing.js
 create mode 100644 test/fixtures/wpt/resource-timing/resources/frameset-timing-frame.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/green-frame.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/green.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/green.html.headers
 create mode 100644 test/fixtures/wpt/resource-timing/resources/iframe-TAO-crossorigin-port.sub.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/iframe-load-from-mem-cache-transfer-size.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/iframe-navigate-back.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/iframe-navigate.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/iframe-refresh.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/iframe-reload-TAO.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/iframe-setdomain.sub.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/iframe-with-delay.sub.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/iframe_TAO_match_origin.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/import.sub.css
 create mode 100644 test/fixtures/wpt/resource-timing/resources/importer.css
 create mode 100644 test/fixtures/wpt/resource-timing/resources/importer.js
 create mode 100644 test/fixtures/wpt/resource-timing/resources/importer_async.js
 create mode 100644 test/fixtures/wpt/resource-timing/resources/importer_dynamic.css
 create mode 100644 test/fixtures/wpt/resource-timing/resources/importer_print.css
 create mode 100644 test/fixtures/wpt/resource-timing/resources/inject_resource_test.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/invalid.jpg
 create mode 100644 test/fixtures/wpt/resource-timing/resources/manifest.json
 create mode 100644 test/fixtures/wpt/resource-timing/resources/navigate_back.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/nested-contexts.js
 create mode 100644 test/fixtures/wpt/resource-timing/resources/nested.css
 create mode 100644 test/fixtures/wpt/resource-timing/resources/notify_parent.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/object-navigate-back.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/object-navigate.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/object-refresh.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/observe-entry.js
 create mode 100644 test/fixtures/wpt/resource-timing/resources/resource-loaders.js
 create mode 100644 test/fixtures/wpt/resource-timing/resources/resource_timing_test0.css
 create mode 100644 test/fixtures/wpt/resource-timing/resources/resource_timing_test0.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/resource_timing_test0.js
 create mode 100644 test/fixtures/wpt/resource-timing/resources/resource_timing_test0.js.headers
 create mode 100644 test/fixtures/wpt/resource-timing/resources/resource_timing_test0.png
 create mode 100644 test/fixtures/wpt/resource-timing/resources/resource_timing_test0.xml
 create mode 100644 test/fixtures/wpt/resource-timing/resources/self_navigation.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/shared-worker.js
 create mode 100644 test/fixtures/wpt/resource-timing/resources/sizes-helper.js
 create mode 100644 test/fixtures/wpt/resource-timing/resources/sw-install.html
 create mode 100644 test/fixtures/wpt/resource-timing/resources/sw.js
 create mode 100644 test/fixtures/wpt/resource-timing/resources/tao-response.js
 create mode 100644 test/fixtures/wpt/resource-timing/resources/webperftestharness.js
 create mode 100644 test/fixtures/wpt/resource-timing/resources/webperftestharnessextension.js
 create mode 100644 test/fixtures/wpt/resource-timing/resources/worker_with_images.js
 create mode 100644 test/fixtures/wpt/resource-timing/same-origin-from-cross-origin-redirect.html
 create mode 100644 test/fixtures/wpt/resource-timing/script-rt-entries.html
 create mode 100644 test/fixtures/wpt/resource-timing/secure-iframe-in-insecure-context.html
 create mode 100644 test/fixtures/wpt/resource-timing/shared-worker-rt-entry.html
 create mode 100644 test/fixtures/wpt/resource-timing/sizes-cache.any.js
 create mode 100644 test/fixtures/wpt/resource-timing/sizes-redirect-img.html
 create mode 100644 test/fixtures/wpt/resource-timing/sizes-redirect.any.js
 create mode 100644 test/fixtures/wpt/resource-timing/status-codes-create-entry.html
 create mode 100644 test/fixtures/wpt/resource-timing/supported_resource_type.any.js
 create mode 100644 test/fixtures/wpt/resource-timing/test_resource_timing.html
 create mode 100644 test/fixtures/wpt/resource-timing/test_resource_timing.https.html
 create mode 100644 test/fixtures/wpt/resource-timing/test_resource_timing.js
 create mode 100644 test/fixtures/wpt/resource-timing/tojson.html
 create mode 100644 test/fixtures/wpt/resource-timing/workerStart-tao-protected.https.html
 create mode 100644 test/fixtures/wpt/resource-timing/worklet-rt-entries.https.html
 create mode 100644 test/fixtures/wpt/resource-timing/xhr-resource-timing.html
 create mode 100644 test/wpt/status/resource-timing.json
 create mode 100644 test/wpt/test-resource-timing.js

diff --git a/doc/api/perf_hooks.md b/doc/api/perf_hooks.md
index 157c0e014e042c..d0f2002cc90b6a 100644
--- a/doc/api/perf_hooks.md
+++ b/doc/api/perf_hooks.md
@@ -49,6 +49,11 @@ Node.js instance. It is similar to [`window.performance`][] in browsers.
 
 <!-- YAML
 added: v8.5.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/44483
+    description: This method must be called with the `performance` object as
+                 the receiver.
 -->
 
 * `name` {string}
@@ -60,6 +65,11 @@ Performance Timeline. If `name` is provided, removes only the named mark.
 
 <!-- YAML
 added: v16.7.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/44483
+    description: This method must be called with the `performance` object as
+                 the receiver.
 -->
 
 * `name` {string}
@@ -73,6 +83,11 @@ Performance Timeline. If `name` is provided, removes only the named measure.
 added:
   - v18.2.0
   - v16.17.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/44483
+    description: This method must be called with the `performance` object as
+                 the receiver.
 -->
 
 * `name` {string}
@@ -147,6 +162,11 @@ are not guaranteed to reflect any correct state of the event loop.
 
 <!-- YAML
 added: v16.7.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/44483
+    description: This method must be called with the `performance` object as
+                 the receiver.
 -->
 
 * Returns: {PerformanceEntry\[]}
@@ -160,6 +180,11 @@ performance entries of certain types or that have certain names, see
 
 <!-- YAML
 added: v16.7.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/44483
+    description: This method must be called with the `performance` object as
+                 the receiver.
 -->
 
 * `name` {string}
@@ -175,6 +200,11 @@ equal to `name`, and optionally, whose `performanceEntry.entryType` is equal to
 
 <!-- YAML
 added: v16.7.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/44483
+    description: This method must be called with the `performance` object as
+                 the receiver.
 -->
 
 * `type` {string}
@@ -189,6 +219,10 @@ is equal to `type`.
 <!-- YAML
 added: v8.5.0
 changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/44483
+    description: This method must be called with the `performance` object as
+                 the receiver.
   - version: v16.0.0
     pr-url: https://github.com/nodejs/node/pull/37136
     description: Updated to conform to the User Timing Level 3 specification.
@@ -244,6 +278,10 @@ Performance Timeline manually with `performance.clearResourceTimings`.
 <!-- YAML
 added: v8.5.0
 changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/44483
+    description: This method must be called with the `performance` object as
+                 the receiver.
   - version: v16.0.0
     pr-url: https://github.com/nodejs/node/pull/37136
     description: Updated to conform to the User Timing Level 3 specification.
@@ -305,6 +343,11 @@ metrics for specific Node.js operational milestones.
 
 <!-- YAML
 added: v8.5.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/44483
+    description: This method must be called with the `performance` object as
+                 the receiver.
 -->
 
 * Returns: {number}
@@ -316,6 +359,11 @@ the start of the current `node` process.
 
 <!-- YAML
 added: v18.8.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/44483
+    description: This method must be called with the `performance` object as
+                 the receiver.
 -->
 
 Sets the global performance resource timing buffer size to the specified number
@@ -393,6 +441,11 @@ invoked.
 
 <!-- YAML
 added: v16.1.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/44483
+    description: This method must be called with the `performance` object as
+                 the receiver.
 -->
 
 An object which is JSON representation of the `performance` object. It
@@ -420,6 +473,11 @@ added: v8.5.0
 
 <!-- YAML
 added: v16.0.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/44483
+    description: This property getter must be called with the
+                 `PerformanceEntry` object as the receiver.
 -->
 
 * {any}
@@ -430,6 +488,11 @@ Additional detail specific to the `entryType`.
 
 <!-- YAML
 added: v8.5.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/44483
+    description: This property getter must be called with the
+                 `PerformanceEntry` object as the receiver.
 -->
 
 * {number}
@@ -441,6 +504,11 @@ be meaningful for all Performance Entry types.
 
 <!-- YAML
 added: v8.5.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/44483
+    description: This property getter must be called with the
+                 `PerformanceEntry` object as the receiver.
 -->
 
 * {string}
@@ -488,6 +556,11 @@ The value may be one of:
 
 <!-- YAML
 added: v8.5.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/44483
+    description: This property getter must be called with the
+                 `PerformanceEntry` object as the receiver.
 -->
 
 * {string}
@@ -522,6 +595,11 @@ The value may be one of:
 
 <!-- YAML
 added: v8.5.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/44483
+    description: This property getter must be called with the
+                 `PerformanceEntry` object as the receiver.
 -->
 
 * {number}
@@ -758,6 +836,11 @@ The constructor of this class is not exposed to users directly.
 added:
   - v18.2.0
   - v16.17.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/44483
+    description: This property getter must be called with the
+                 `PerformanceResourceTiming` object as the receiver.
 -->
 
 * {number}
@@ -772,6 +855,11 @@ will always return 0.
 added:
   - v18.2.0
   - v16.17.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/44483
+    description: This property getter must be called with the
+                 `PerformanceResourceTiming` object as the receiver.
 -->
 
 * {number}
@@ -785,6 +873,11 @@ of the fetch which initiates the redirect.
 added:
   - v18.2.0
   - v16.17.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/44483
+    description: This property getter must be called with the
+                 `PerformanceResourceTiming` object as the receiver.
 -->
 
 * {number}
@@ -798,6 +891,11 @@ receiving the last byte of the response of the last redirect.
 added:
   - v18.2.0
   - v16.17.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/44483
+    description: This property getter must be called with the
+                 `PerformanceResourceTiming` object as the receiver.
 -->
 
 * {number}
@@ -811,6 +909,11 @@ to fetch the resource.
 added:
   - v18.2.0
   - v16.17.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/44483
+    description: This property getter must be called with the
+                 `PerformanceResourceTiming` object as the receiver.
 -->
 
 * {number}
@@ -824,6 +927,11 @@ the domain name lookup for the resource.
 added:
   - v18.2.0
   - v16.17.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/44483
+    description: This property getter must be called with the
+                 `PerformanceResourceTiming` object as the receiver.
 -->
 
 * {number}
@@ -837,6 +945,11 @@ after the Node.js finished the domain name lookup for the resource.
 added:
   - v18.2.0
   - v16.17.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/44483
+    description: This property getter must be called with the
+                 `PerformanceResourceTiming` object as the receiver.
 -->
 
 * {number}
@@ -851,6 +964,11 @@ the resource.
 added:
   - v18.2.0
   - v16.17.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/44483
+    description: This property getter must be called with the
+                 `PerformanceResourceTiming` object as the receiver.
 -->
 
 * {number}
@@ -865,6 +983,11 @@ the resource.
 added:
   - v18.2.0
   - v16.17.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/44483
+    description: This property getter must be called with the
+                 `PerformanceResourceTiming` object as the receiver.
 -->
 
 * {number}
@@ -878,6 +1001,11 @@ before Node.js starts the handshake process to secure the current connection.
 added:
   - v18.2.0
   - v16.17.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/44483
+    description: This property getter must be called with the
+                 `PerformanceResourceTiming` object as the receiver.
 -->
 
 * {number}
@@ -891,6 +1019,11 @@ before Node.js receives the first byte of the response from the server.
 added:
   - v18.2.0
   - v16.17.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/44483
+    description: This property getter must be called with the
+                 `PerformanceResourceTiming` object as the receiver.
 -->
 
 * {number}
@@ -905,6 +1038,11 @@ the transport connection is closed, whichever comes first.
 added:
   - v18.2.0
   - v16.17.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/44483
+    description: This property getter must be called with the
+                 `PerformanceResourceTiming` object as the receiver.
 -->
 
 * {number}
@@ -918,6 +1056,11 @@ includes the response header fields plus the response payload body.
 added:
   - v18.2.0
   - v16.17.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/44483
+    description: This property getter must be called with the
+                 `PerformanceResourceTiming` object as the receiver.
 -->
 
 * {number}
@@ -932,6 +1075,11 @@ content-codings.
 added:
   - v18.2.0
   - v16.17.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/44483
+    description: This property getter must be called with the
+                 `PerformanceResourceTiming` object as the receiver.
 -->
 
 * {number}
@@ -946,6 +1094,11 @@ content-codings.
 added:
   - v18.2.0
   - v16.17.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/44483
+    description: This method must be called with the
+                 `PerformanceResourceTiming` object as the receiver.
 -->
 
 Returns a `object` that is the JSON representation of the
diff --git a/lib/internal/bootstrap/browser.js b/lib/internal/bootstrap/browser.js
index d0c01ca2a512be..92d57688e21115 100644
--- a/lib/internal/bootstrap/browser.js
+++ b/lib/internal/bootstrap/browser.js
@@ -75,8 +75,8 @@ exposeInterface(globalThis, 'Blob', buffer.Blob);
 // https://www.w3.org/TR/hr-time-2/#the-performance-attribute
 const perf_hooks = require('perf_hooks');
 exposeInterface(globalThis, 'Performance', perf_hooks.Performance);
-defineReplacableAttribute(globalThis, 'performance',
-                          perf_hooks.performance);
+defineReplaceableAttribute(globalThis, 'performance',
+                           perf_hooks.performance);
 
 function createGlobalConsole() {
   const consoleFromNode =
@@ -114,14 +114,33 @@ function exposeGetterAndSetter(target, name, getter, setter = undefined) {
   });
 }
 
-// https://heycam.github.io/webidl/#Replaceable
-function defineReplacableAttribute(target, name, value) {
+// https://webidl.spec.whatwg.org/#Replaceable
+function defineReplaceableAttribute(target, name, value) {
+  let slot = value;
+
+  // https://webidl.spec.whatwg.org/#dfn-attribute-getter
+  function get() {
+    return slot;
+  }
+  ObjectDefineProperty(get, 'name', {
+    __proto__: null,
+    value: `get ${name}`,
+  });
+
+  function set(value) {
+    slot = value;
+  }
+  ObjectDefineProperty(set, 'name', {
+    __proto__: null,
+    value: `set ${name}`,
+  });
+
   ObjectDefineProperty(target, name, {
     __proto__: null,
-    writable: true,
     enumerable: true,
     configurable: true,
-    value,
+    get,
+    set,
   });
 }
 
diff --git a/lib/internal/event_target.js b/lib/internal/event_target.js
index 2be1b9cf0b9f39..c60e80d5c5d4c7 100644
--- a/lib/internal/event_target.js
+++ b/lib/internal/event_target.js
@@ -34,7 +34,7 @@ const {
     ERR_INVALID_THIS,
   }
 } = require('internal/errors');
-const { validateObject, validateString } = require('internal/validators');
+const { validateObject, validateString, validateInternalField } = require('internal/validators');
 
 const {
   customInspectSymbol,
@@ -492,6 +492,7 @@ function initEventTarget(self) {
   self[kEvents] = new SafeMap();
   self[kMaxEventTargetListeners] = EventEmitter.defaultMaxListeners;
   self[kMaxEventTargetListenersWarned] = false;
+  self[kHandlers] = new SafeMap();
 }
 
 class EventTarget {
@@ -1021,34 +1022,46 @@ function makeEventHandler(handler) {
 
 function defineEventHandler(emitter, name) {
   // 8.1.5.1 Event handlers - basically `on[eventName]` attributes
-  ObjectDefineProperty(emitter, `on${name}`, {
+  const propName = `on${name}`;
+  function get() {
+    validateInternalField(this, kHandlers, 'EventTarget');
+    return this[kHandlers]?.get(name)?.handler ?? null;
+  }
+  ObjectDefineProperty(get, 'name', {
     __proto__: null,
-    get() {
-      return this[kHandlers]?.get(name)?.handler ?? null;
-    },
-    set(value) {
-      if (!this[kHandlers]) {
-        this[kHandlers] = new SafeMap();
+    value: `get ${propName}`,
+  });
+
+  function set(value) {
+    validateInternalField(this, kHandlers, 'EventTarget');
+    let wrappedHandler = this[kHandlers]?.get(name);
+    if (wrappedHandler) {
+      if (typeof wrappedHandler.handler === 'function') {
+        this[kEvents].get(name).size--;
+        const size = this[kEvents].get(name).size;
+        this[kRemoveListener](size, name, wrappedHandler.handler, false);
       }
-      let wrappedHandler = this[kHandlers]?.get(name);
-      if (wrappedHandler) {
-        if (typeof wrappedHandler.handler === 'function') {
-          this[kEvents].get(name).size--;
-          const size = this[kEvents].get(name).size;
-          this[kRemoveListener](size, name, wrappedHandler.handler, false);
-        }
-        wrappedHandler.handler = value;
-        if (typeof wrappedHandler.handler === 'function') {
-          this[kEvents].get(name).size++;
-          const size = this[kEvents].get(name).size;
-          this[kNewListener](size, name, value, false, false, false, false);
-        }
-      } else {
-        wrappedHandler = makeEventHandler(value);
-        this.addEventListener(name, wrappedHandler);
+      wrappedHandler.handler = value;
+      if (typeof wrappedHandler.handler === 'function') {
+        this[kEvents].get(name).size++;
+        const size = this[kEvents].get(name).size;
+        this[kNewListener](size, name, value, false, false, false, false);
       }
-      this[kHandlers].set(name, wrappedHandler);
-    },
+    } else {
+      wrappedHandler = makeEventHandler(value);
+      this.addEventListener(name, wrappedHandler);
+    }
+    this[kHandlers].set(name, wrappedHandler);
+  }
+  ObjectDefineProperty(set, 'name', {
+    __proto__: null,
+    value: `set ${propName}`,
+  });
+
+  ObjectDefineProperty(emitter, propName, {
+    __proto__: null,
+    get,
+    set,
     configurable: true,
     enumerable: true
   });
diff --git a/lib/internal/perf/observe.js b/lib/internal/perf/observe.js
index f84bb69bbddae2..6d8735039fb87d 100644
--- a/lib/internal/perf/observe.js
+++ b/lib/internal/perf/observe.js
@@ -16,9 +16,11 @@ const {
   ObjectDefineProperties,
   ObjectFreeze,
   ObjectKeys,
+  ReflectConstruct,
   SafeMap,
   SafeSet,
   Symbol,
+  SymbolToStringTag,
 } = primordials;
 
 const {
@@ -36,12 +38,13 @@ const {
 } = internalBinding('performance');
 
 const {
-  InternalPerformanceEntry,
   isPerformanceEntry,
+  createNodePerformanceEntry,
 } = require('internal/perf/performance_entry');
 
 const {
   codes: {
+    ERR_ILLEGAL_CONSTRUCTOR,
     ERR_INVALID_ARG_VALUE,
     ERR_INVALID_ARG_TYPE,
     ERR_MISSING_ARGS,
@@ -51,6 +54,7 @@ const {
 const {
   validateFunction,
   validateObject,
+  validateInternalField,
 } = require('internal/validators');
 
 const {
@@ -58,6 +62,7 @@ const {
   deprecate,
   lazyDOMException,
   kEmptyObject,
+  kEnumerableProperty,
 } = require('internal/util');
 
 const {
@@ -68,6 +73,7 @@ const { inspect } = require('util');
 
 const { now } = require('internal/perf/utils');
 
+const kBuffer = Symbol('kBuffer');
 const kDispatch = Symbol('kDispatch');
 const kMaybeBuffer = Symbol('kMaybeBuffer');
 const kDeprecatedFields = Symbol('kDeprecatedFields');
@@ -167,34 +173,39 @@ function maybeIncrementObserverCount(type) {
 }
 
 class PerformanceObserverEntryList {
-  #buffer = [];
-
-  constructor(entries) {
-    this.#buffer = ArrayPrototypeSort(entries, (first, second) => {
-      return first.startTime - second.startTime;
-    });
+  constructor() {
+    throw new ERR_ILLEGAL_CONSTRUCTOR();
   }
 
   getEntries() {
-    return ArrayPrototypeSlice(this.#buffer);
+    validateInternalField(this, kBuffer, 'PerformanceObserverEntryList');
+    return ArrayPrototypeSlice(this[kBuffer]);
   }
 
   getEntriesByType(type) {
+    validateInternalField(this, kBuffer, 'PerformanceObserverEntryList');
+    if (arguments.length === 0) {
+      throw new ERR_MISSING_ARGS('type');
+    }
     type = `${type}`;
     return ArrayPrototypeFilter(
-      this.#buffer,
+      this[kBuffer],
       (entry) => entry.entryType === type);
   }
 
-  getEntriesByName(name, type) {
+  getEntriesByName(name, type = undefined) {
+    validateInternalField(this, kBuffer, 'PerformanceObserverEntryList');
+    if (arguments.length === 0) {
+      throw new ERR_MISSING_ARGS('name');
+    }
     name = `${name}`;
     if (type != null /** not nullish */) {
       return ArrayPrototypeFilter(
-        this.#buffer,
+        this[kBuffer],
         (entry) => entry.name === name && entry.entryType === type);
     }
     return ArrayPrototypeFilter(
-      this.#buffer,
+      this[kBuffer],
       (entry) => entry.name === name);
   }
 
@@ -206,9 +217,29 @@ class PerformanceObserverEntryList {
       depth: options.depth == null ? null : options.depth - 1
     };
 
-    return `PerformanceObserverEntryList ${inspect(this.#buffer, opts)}`;
+    return `PerformanceObserverEntryList ${inspect(this[kBuffer], opts)}`;
   }
 }
+ObjectDefineProperties(PerformanceObserverEntryList.prototype, {
+  getEntries: kEnumerableProperty,
+  getEntriesByType: kEnumerableProperty,
+  getEntriesByName: kEnumerableProperty,
+  [SymbolToStringTag]: {
+    __proto__: null,
+    writable: false,
+    enumerable: false,
+    configurable: true,
+    value: 'PerformanceObserverEntryList',
+  },
+});
+
+function createPerformanceObserverEntryList(entries) {
+  return ReflectConstruct(function PerformanceObserverEntryList() {
+    this[kBuffer] = ArrayPrototypeSort(entries, (first, second) => {
+      return first.startTime - second.startTime;
+    });
+  }, [], PerformanceObserverEntryList);
+}
 
 class PerformanceObserver {
   #buffer = [];
@@ -319,7 +350,7 @@ class PerformanceObserver {
   }
 
   [kDispatch]() {
-    this.#callback(new PerformanceObserverEntryList(this.takeRecords()),
+    this.#callback(createPerformanceObserverEntryList(this.takeRecords()),
                    this);
   }
 
@@ -338,7 +369,23 @@ class PerformanceObserver {
       buffer: this.#buffer,
     }, opts)}`;
   }
+
+  [SymbolToStringTag]() {
+    return 'PerformanceObserver';
+  }
 }
+ObjectDefineProperties(PerformanceObserver.prototype, {
+  observe: kEnumerableProperty,
+  disconnect: kEnumerableProperty,
+  takeRecords: kEnumerableProperty,
+  [SymbolToStringTag]: {
+    __proto__: null,
+    writable: false,
+    enumerable: false,
+    configurable: true,
+    value: 'PerformanceObserver',
+  },
+});
 
 /**
  * https://www.w3.org/TR/performance-timeline/#dfn-queue-a-performanceentry
@@ -485,7 +532,7 @@ function filterBufferMapByNameAndType(name, type) {
 
 function observerCallback(name, type, startTime, duration, details) {
   const entry =
-    new InternalPerformanceEntry(
+    createNodePerformanceEntry(
       name,
       type,
       startTime,
@@ -542,7 +589,7 @@ function stopPerf(target, key, context = {}) {
     return;
   }
   const startTime = ctx.startTime;
-  const entry = new InternalPerformanceEntry(
+  const entry = createNodePerformanceEntry(
     ctx.name,
     ctx.type,
     startTime,
diff --git a/lib/internal/perf/performance.js b/lib/internal/perf/performance.js
index 610523853f86f5..f7a12129673af4 100644
--- a/lib/internal/perf/performance.js
+++ b/lib/internal/perf/performance.js
@@ -1,9 +1,10 @@
 'use strict';
 
 const {
-  ObjectDefineProperty,
   ObjectDefineProperties,
-  ObjectSetPrototypeOf,
+  ReflectConstruct,
+  Symbol,
+  SymbolToStringTag,
 } = primordials;
 
 const {
@@ -17,6 +18,8 @@ const {
   EventTarget,
   Event,
   kTrustEvent,
+  initEventTarget,
+  defineEventHandler,
 } = require('internal/event_target');
 
 const { now } = require('internal/perf/utils');
@@ -38,13 +41,16 @@ const {
 const { eventLoopUtilization } = require('internal/perf/event_loop_utilization');
 const nodeTiming = require('internal/perf/nodetiming');
 const timerify = require('internal/perf/timerify');
-const { customInspectSymbol: kInspect } = require('internal/util');
+const { customInspectSymbol: kInspect, kEnumerableProperty, kEmptyObject } = require('internal/util');
 const { inspect } = require('util');
+const { validateInternalField } = require('internal/validators');
 
 const {
   getTimeOriginTimestamp
 } = internalBinding('performance');
 
+const kPerformanceBrand = Symbol('performance');
+
 class Performance extends EventTarget {
   constructor() {
     throw new ERR_ILLEGAL_CONSTRUCTOR();
@@ -63,121 +69,135 @@ class Performance extends EventTarget {
       timeOrigin: this.timeOrigin,
     }, opts)}`;
   }
-}
 
-function toJSON() {
-  return {
-    nodeTiming: this.nodeTiming,
-    timeOrigin: this.timeOrigin,
-    eventLoopUtilization: this.eventLoopUtilization()
-  };
-}
+  clearMarks(name = undefined) {
+    validateInternalField(this, kPerformanceBrand, 'Performance');
+    if (name !== undefined) {
+      name = `${name}`;
+    }
+    clearMarkTimings(name);
+    clearEntriesFromBuffer('mark', name);
+  }
 
-function clearMarks(name) {
-  if (name !== undefined) {
-    name = `${name}`;
+  clearMeasures(name = undefined) {
+    validateInternalField(this, kPerformanceBrand, 'Performance');
+    if (name !== undefined) {
+      name = `${name}`;
+    }
+    clearEntriesFromBuffer('measure', name);
   }
-  clearMarkTimings(name);
-  clearEntriesFromBuffer('mark', name);
-}
 
-function clearMeasures(name) {
-  if (name !== undefined) {
-    name = `${name}`;
+  clearResourceTimings(name = undefined) {
+    validateInternalField(this, kPerformanceBrand, 'Performance');
+    if (name !== undefined) {
+      name = `${name}`;
+    }
+    clearEntriesFromBuffer('resource', name);
+  }
+
+  getEntries() {
+    validateInternalField(this, kPerformanceBrand, 'Performance');
+    return filterBufferMapByNameAndType();
   }
-  clearEntriesFromBuffer('measure', name);
-}
 
-function clearResourceTimings(name) {
-  if (name !== undefined) {
+  getEntriesByName(name) {
+    validateInternalField(this, kPerformanceBrand, 'Performance');
+    if (arguments.length === 0) {
+      throw new ERR_MISSING_ARGS('name');
+    }
     name = `${name}`;
+    return filterBufferMapByNameAndType(name, undefined);
   }
-  clearEntriesFromBuffer('resource', name);
-}
 
-function getEntries() {
-  return filterBufferMapByNameAndType();
-}
+  getEntriesByType(type) {
+    validateInternalField(this, kPerformanceBrand, 'Performance');
+    if (arguments.length === 0) {
+      throw new ERR_MISSING_ARGS('type');
+    }
+    type = `${type}`;
+    return filterBufferMapByNameAndType(undefined, type);
+  }
 
-function getEntriesByName(name) {
-  if (arguments.length === 0) {
-    throw new ERR_MISSING_ARGS('name');
+  mark(name, options = kEmptyObject) {
+    validateInternalField(this, kPerformanceBrand, 'Performance');
+    if (arguments.length === 0) {
+      throw new ERR_MISSING_ARGS('name');
+    }
+    return mark(name, options);
   }
-  name = `${name}`;
-  return filterBufferMapByNameAndType(name, undefined);
-}
 
-function getEntriesByType(type) {
-  if (arguments.length === 0) {
-    throw new ERR_MISSING_ARGS('type');
+  measure(name, startOrMeasureOptions = kEmptyObject, endMark = undefined) {
+    validateInternalField(this, kPerformanceBrand, 'Performance');
+    if (arguments.length === 0) {
+      throw new ERR_MISSING_ARGS('name');
+    }
+    return measure(name, startOrMeasureOptions, endMark);
   }
-  type = `${type}`;
-  return filterBufferMapByNameAndType(undefined, type);
-}
 
-class InternalPerformance extends EventTarget {}
-InternalPerformance.prototype.constructor = Performance.prototype.constructor;
-ObjectSetPrototypeOf(InternalPerformance.prototype, Performance.prototype);
+  now() {
+    validateInternalField(this, kPerformanceBrand, 'Performance');
+    return now();
+  }
+
+  setResourceTimingBufferSize(maxSize) {
+    validateInternalField(this, kPerformanceBrand, 'Performance');
+    if (arguments.length === 0) {
+      throw new ERR_MISSING_ARGS('maxSize');
+    }
+    return setResourceTimingBufferSize(maxSize);
+  }
+
+  get timeOrigin() {
+    validateInternalField(this, kPerformanceBrand, 'Performance');
+    return getTimeOriginTimestamp();
+  }
+
+  toJSON() {
+    validateInternalField(this, kPerformanceBrand, 'Performance');
+    return {
+      nodeTiming: this.nodeTiming,
+      timeOrigin: this.timeOrigin,
+      eventLoopUtilization: this.eventLoopUtilization()
+    };
+  }
+}
 
 ObjectDefineProperties(Performance.prototype, {
-  clearMarks: {
-    __proto__: null,
-    configurable: true,
+  clearMarks: kEnumerableProperty,
+  clearMeasures: kEnumerableProperty,
+  clearResourceTimings: kEnumerableProperty,
+  getEntries: kEnumerableProperty,
+  getEntriesByName: kEnumerableProperty,
+  getEntriesByType: kEnumerableProperty,
+  mark: kEnumerableProperty,
+  measure: kEnumerableProperty,
+  now: kEnumerableProperty,
+  timeOrigin: kEnumerableProperty,
+  toJSON: kEnumerableProperty,
+  setResourceTimingBufferSize: kEnumerableProperty,
+  [SymbolToStringTag]: {
+    __proto__: null,
+    writable: false,
     enumerable: false,
-    value: clearMarks,
-  },
-  clearMeasures: {
-    __proto__: null,
     configurable: true,
-    enumerable: false,
-    value: clearMeasures,
-  },
-  clearResourceTimings: {
-    __proto__: null,
-    configurable: true,
-    enumerable: false,
-    value: clearResourceTimings,
+    value: 'Performance',
   },
+
+  // Node.js specific extensions.
   eventLoopUtilization: {
     __proto__: null,
     configurable: true,
+    // Node.js specific extensions.
     enumerable: false,
+    writable: true,
     value: eventLoopUtilization,
   },
-  getEntries: {
-    __proto__: null,
-    configurable: true,
-    enumerable: false,
-    value: getEntries,
-  },
-  getEntriesByName: {
-    __proto__: null,
-    configurable: true,
-    enumerable: false,
-    value: getEntriesByName,
-  },
-  getEntriesByType: {
-    __proto__: null,
-    configurable: true,
-    enumerable: false,
-    value: getEntriesByType,
-  },
-  mark: {
-    __proto__: null,
-    configurable: true,
-    enumerable: false,
-    value: mark,
-  },
-  measure: {
-    __proto__: null,
-    configurable: true,
-    enumerable: false,
-    value: measure,
-  },
   nodeTiming: {
     __proto__: null,
     configurable: true,
+    // Node.js specific extensions.
     enumerable: false,
+    writable: true,
     value: nodeTiming,
   },
   // In the browser, this function is not public.  However, it must be used inside fetch
@@ -185,55 +205,30 @@ ObjectDefineProperties(Performance.prototype, {
   markResourceTiming: {
     __proto__: null,
     configurable: true,
+    // Node.js specific extensions.
     enumerable: false,
+    writable: true,
     value: markResourceTiming,
   },
-  now: {
-    __proto__: null,
-    configurable: true,
-    enumerable: false,
-    value: now,
-  },
-  setResourceTimingBufferSize: {
-    __proto__: null,
-    configurable: true,
-    enumerable: false,
-    value: setResourceTimingBufferSize
-  },
   timerify: {
     __proto__: null,
     configurable: true,
+    // Node.js specific extensions.
     enumerable: false,
+    writable: true,
     value: timerify,
   },
-  // This would be updated during pre-execution in case
-  // the process is launched from a snapshot.
-  // TODO(joyeecheung): we may want to warn about access to
-  // this during snapshot building.
-  timeOrigin: {
-    __proto__: null,
-    configurable: true,
-    enumerable: true,
-    value: getTimeOriginTimestamp(),
-  },
-  toJSON: {
-    __proto__: null,
-    configurable: true,
-    enumerable: true,
-    value: toJSON,
-  }
 });
+defineEventHandler(Performance.prototype, 'resourcetimingbufferfull');
 
-function refreshTimeOrigin() {
-  ObjectDefineProperty(Performance.prototype, 'timeOrigin', {
-    __proto__: null,
-    configurable: true,
-    enumerable: true,
-    value: getTimeOriginTimestamp(),
-  });
+function createPerformance() {
+  return ReflectConstruct(function Performance() {
+    initEventTarget(this);
+    this[kPerformanceBrand] = true;
+  }, [], Performance);
 }
 
-const performance = new InternalPerformance();
+const performance = createPerformance();
 
 function dispatchBufferFull(type) {
   const event = new Event(type, {
@@ -246,5 +241,4 @@ setDispatchBufferFull(dispatchBufferFull);
 module.exports = {
   Performance,
   performance,
-  refreshTimeOrigin
 };
diff --git a/lib/internal/perf/performance_entry.js b/lib/internal/perf/performance_entry.js
index 759f1315d5b6c2..e472a9b328c742 100644
--- a/lib/internal/perf/performance_entry.js
+++ b/lib/internal/perf/performance_entry.js
@@ -1,7 +1,8 @@
 'use strict';
 
 const {
-  ObjectSetPrototypeOf,
+  ObjectDefineProperties,
+  ReflectConstruct,
   Symbol,
 } = primordials;
 
@@ -12,16 +13,17 @@ const {
 } = require('internal/errors');
 
 const {
-  customInspectSymbol: kInspect,
+  customInspectSymbol: kInspect, kEnumerableProperty,
 } = require('internal/util');
+const { validateInternalField } = require('internal/validators');
 
 const { inspect } = require('util');
 
-const kName = Symbol('kName');
-const kType = Symbol('kType');
-const kStart = Symbol('kStart');
-const kDuration = Symbol('kDuration');
-const kDetail = Symbol('kDetail');
+const kName = Symbol('PerformanceEntry.Name');
+const kEntryType = Symbol('PerformanceEntry.EntryType');
+const kStartTime = Symbol('PerformanceEntry.StartTime');
+const kDuration = Symbol('PerformanceEntry.Duration');
+const kDetail = Symbol('NodePerformanceEntry.Detail');
 
 function isPerformanceEntry(obj) {
   return obj?.[kName] !== undefined;
@@ -32,15 +34,25 @@ class PerformanceEntry {
     throw new ERR_ILLEGAL_CONSTRUCTOR();
   }
 
-  get name() { return this[kName]; }
-
-  get entryType() { return this[kType]; }
+  get name() {
+    validateInternalField(this, kName, 'PerformanceEntry');
+    return this[kName];
+  }
 
-  get startTime() { return this[kStart]; }
+  get entryType() {
+    validateInternalField(this, kEntryType, 'PerformanceEntry');
+    return this[kEntryType];
+  }
 
-  get duration() { return this[kDuration]; }
+  get startTime() {
+    validateInternalField(this, kStartTime, 'PerformanceEntry');
+    return this[kStartTime];
+  }
 
-  get detail() { return this[kDetail]; }
+  get duration() {
+    validateInternalField(this, kDuration, 'PerformanceEntry');
+    return this[kDuration];
+  }
 
   [kInspect](depth, options) {
     if (depth < 0) return this;
@@ -54,33 +66,68 @@ class PerformanceEntry {
   }
 
   toJSON() {
+    validateInternalField(this, kName, 'PerformanceEntry');
     return {
-      name: this.name,
-      entryType: this.entryType,
-      startTime: this.startTime,
-      duration: this.duration,
-      detail: this.detail,
+      name: this[kName],
+      entryType: this[kEntryType],
+      startTime: this[kStartTime],
+      duration: this[kDuration],
     };
   }
 }
+ObjectDefineProperties(PerformanceEntry.prototype, {
+  name: kEnumerableProperty,
+  entryType: kEnumerableProperty,
+  startTime: kEnumerableProperty,
+  duration: kEnumerableProperty,
+  toJSON: kEnumerableProperty,
+});
+
+function initPerformanceEntry(entry, name, type, start, duration) {
+  entry[kName] = name;
+  entry[kEntryType] = type;
+  entry[kStartTime] = start;
+  entry[kDuration] = duration;
+}
 
-class InternalPerformanceEntry {
-  constructor(name, type, start, duration, detail) {
-    this[kName] = name;
-    this[kType] = type;
-    this[kStart] = start;
-    this[kDuration] = duration;
-    this[kDetail] = detail;
+function createPerformanceEntry(name, type, start, duration) {
+  return ReflectConstruct(function PerformanceEntry() {
+    initPerformanceEntry(this, name, type, start, duration);
+  }, [], PerformanceEntry);
+}
+
+/**
+ * Node.js specific extension to PerformanceEntry.
+ */
+class NodePerformanceEntry extends PerformanceEntry {
+  get detail() {
+    validateInternalField(this, kDetail, 'NodePerformanceEntry');
+    return this[kDetail];
+  }
+
+  toJSON() {
+    validateInternalField(this, kName, 'PerformanceEntry');
+    return {
+      name: this[kName],
+      entryType: this[kEntryType],
+      startTime: this[kStartTime],
+      duration: this[kDuration],
+      detail: this[kDetail],
+    };
   }
 }
 
-InternalPerformanceEntry.prototype.constructor = PerformanceEntry;
-ObjectSetPrototypeOf(
-  InternalPerformanceEntry.prototype,
-  PerformanceEntry.prototype);
+function createNodePerformanceEntry(name, type, start, duration, detail) {
+  return ReflectConstruct(function PerformanceEntry() {
+    initPerformanceEntry(this, name, type, start, duration);
+    this[kDetail] = detail;
+  }, [], NodePerformanceEntry);
+}
 
 module.exports = {
-  InternalPerformanceEntry,
+  initPerformanceEntry,
+  createPerformanceEntry,
   PerformanceEntry,
   isPerformanceEntry,
+  createNodePerformanceEntry,
 };
diff --git a/lib/internal/perf/resource_timing.js b/lib/internal/perf/resource_timing.js
index 33e0d9e5ce936b..3cb8caf76d9d57 100644
--- a/lib/internal/perf/resource_timing.js
+++ b/lib/internal/perf/resource_timing.js
@@ -1,33 +1,32 @@
 'use strict';
 // https://developer.mozilla.org/en-US/docs/Web/API/PerformanceResourceTiming
 
-const { InternalPerformanceEntry } = require('internal/perf/performance_entry');
-const { SymbolToStringTag } = primordials;
+const {
+  ObjectDefineProperties,
+  ObjectSetPrototypeOf,
+  ReflectConstruct,
+  Symbol,
+  SymbolToStringTag
+} = primordials;
+const { initPerformanceEntry, PerformanceEntry } = require('internal/perf/performance_entry');
 const assert = require('internal/assert');
 const { enqueue, bufferResourceTiming } = require('internal/perf/observe');
-const { Symbol, ObjectSetPrototypeOf } = primordials;
-
-const kCacheMode = Symbol('kCacheMode');
-const kRequestedUrl = Symbol('kRequestedUrl');
-const kTimingInfo = Symbol('kTimingInfo');
-const kInitiatorType = Symbol('kInitiatorType');
-
 const {
   codes: {
     ERR_ILLEGAL_CONSTRUCTOR,
   }
 } = require('internal/errors');
+const { validateInternalField } = require('internal/validators');
+const { kEnumerableProperty } = require('internal/util');
 
-class InternalPerformanceResourceTiming extends InternalPerformanceEntry {
-  constructor(requestedUrl, initiatorType, timingInfo, cacheMode = '') {
-    super(requestedUrl, 'resource');
-    this[kInitiatorType] = initiatorType;
-    this[kRequestedUrl] = requestedUrl;
-    // https://fetch.spec.whatwg.org/#fetch-timing-info
-    // This class is using timingInfo assuming it's already validated.
-    // The spec doesn't say to validate it in the class construction.
-    this[kTimingInfo] = timingInfo;
-    this[kCacheMode] = cacheMode;
+const kCacheMode = Symbol('kCacheMode');
+const kRequestedUrl = Symbol('kRequestedUrl');
+const kTimingInfo = Symbol('kTimingInfo');
+const kInitiatorType = Symbol('kInitiatorType');
+
+class PerformanceResourceTiming extends PerformanceEntry {
+  constructor() {
+    throw new ERR_ILLEGAL_CONSTRUCTOR();
   }
 
   get [SymbolToStringTag]() {
@@ -35,84 +34,104 @@ class InternalPerformanceResourceTiming extends InternalPerformanceEntry {
   }
 
   get name() {
+    validateInternalField(this, kRequestedUrl, 'PerformanceResourceTiming');
     return this[kRequestedUrl];
   }
 
   get startTime() {
+    validateInternalField(this, kTimingInfo, 'PerformanceResourceTiming');
     return this[kTimingInfo].startTime;
   }
 
   get duration() {
+    validateInternalField(this, kTimingInfo, 'PerformanceResourceTiming');
     return this[kTimingInfo].endTime - this[kTimingInfo].startTime;
   }
 
   get initiatorType() {
+    validateInternalField(this, kInitiatorType, 'PerformanceResourceTiming');
     return this[kInitiatorType];
   }
 
   get workerStart() {
+    validateInternalField(this, kTimingInfo, 'PerformanceResourceTiming');
     return this[kTimingInfo].finalServiceWorkerStartTime;
   }
 
   get redirectStart() {
+    validateInternalField(this, kTimingInfo, 'PerformanceResourceTiming');
     return this[kTimingInfo].redirectStartTime;
   }
 
   get redirectEnd() {
+    validateInternalField(this, kTimingInfo, 'PerformanceResourceTiming');
     return this[kTimingInfo].redirectEndTime;
   }
 
   get fetchStart() {
+    validateInternalField(this, kTimingInfo, 'PerformanceResourceTiming');
     return this[kTimingInfo].postRedirectStartTime;
   }
 
   get domainLookupStart() {
+    validateInternalField(this, kTimingInfo, 'PerformanceResourceTiming');
     return this[kTimingInfo].finalConnectionTimingInfo?.domainLookupStartTime;
   }
 
   get domainLookupEnd() {
+    validateInternalField(this, kTimingInfo, 'PerformanceResourceTiming');
     return this[kTimingInfo].finalConnectionTimingInfo?.domainLookupEndTime;
   }
 
   get connectStart() {
+    validateInternalField(this, kTimingInfo, 'PerformanceResourceTiming');
     return this[kTimingInfo].finalConnectionTimingInfo?.connectionStartTime;
   }
 
   get connectEnd() {
+    validateInternalField(this, kTimingInfo, 'PerformanceResourceTiming');
     return this[kTimingInfo].finalConnectionTimingInfo?.connectionEndTime;
   }
 
   get secureConnectionStart() {
+    validateInternalField(this, kTimingInfo, 'PerformanceResourceTiming');
     return this[kTimingInfo]
       .finalConnectionTimingInfo?.secureConnectionStartTime;
   }
 
   get nextHopProtocol() {
+    validateInternalField(this, kTimingInfo, 'PerformanceResourceTiming');
     return this[kTimingInfo]
       .finalConnectionTimingInfo?.ALPNNegotiatedProtocol;
   }
 
   get requestStart() {
+    validateInternalField(this, kTimingInfo, 'PerformanceResourceTiming');
     return this[kTimingInfo].finalNetworkRequestStartTime;
   }
 
   get responseStart() {
+    validateInternalField(this, kTimingInfo, 'PerformanceResourceTiming');
     return this[kTimingInfo].finalNetworkResponseStartTime;
   }
 
   get responseEnd() {
+    validateInternalField(this, kTimingInfo, 'PerformanceResourceTiming');
     return this[kTimingInfo].endTime;
   }
 
   get encodedBodySize() {
+    validateInternalField(this, kTimingInfo, 'PerformanceResourceTiming');
     return this[kTimingInfo].encodedBodySize;
   }
 
   get decodedBodySize() {
+    validateInternalField(this, kTimingInfo, 'PerformanceResourceTiming');
     return this[kTimingInfo].decodedBodySize;
   }
 
   get transferSize() {
+    validateInternalField(this, kTimingInfo, 'PerformanceResourceTiming');
     if (this[kCacheMode] === 'local') return 0;
     if (this[kCacheMode] === 'validated') return 300;
 
@@ -120,6 +139,7 @@ class InternalPerformanceResourceTiming extends InternalPerformanceEntry {
   }
 
   toJSON() {
+    validateInternalField(this, kInitiatorType, 'PerformanceResourceTiming');
     return {
       name: this.name,
       entryType: this.entryType,
@@ -146,10 +166,38 @@ class InternalPerformanceResourceTiming extends InternalPerformanceEntry {
   }
 }
 
-class PerformanceResourceTiming extends InternalPerformanceResourceTiming {
-  constructor() {
-    throw new ERR_ILLEGAL_CONSTRUCTOR();
-  }
+ObjectDefineProperties(PerformanceResourceTiming.prototype, {
+  initiatorType: kEnumerableProperty,
+  nextHopProtocol: kEnumerableProperty,
+  workerStart: kEnumerableProperty,
+  redirectStart: kEnumerableProperty,
+  redirectEnd: kEnumerableProperty,
+  fetchStart: kEnumerableProperty,
+  domainLookupStart: kEnumerableProperty,
+  domainLookupEnd: kEnumerableProperty,
+  connectStart: kEnumerableProperty,
+  connectEnd: kEnumerableProperty,
+  secureConnectionStart: kEnumerableProperty,
+  requestStart: kEnumerableProperty,
+  responseStart: kEnumerableProperty,
+  responseEnd: kEnumerableProperty,
+  transferSize: kEnumerableProperty,
+  encodedBodySize: kEnumerableProperty,
+  decodedBodySize: kEnumerableProperty,
+  toJSON: kEnumerableProperty,
+});
+
+function createPerformanceResourceTiming(requestedUrl, initiatorType, timingInfo, cacheMode = '') {
+  return ReflectConstruct(function PerformanceResourceTiming() {
+    initPerformanceEntry(this, requestedUrl, 'resource');
+    this[kInitiatorType] = initiatorType;
+    this[kRequestedUrl] = requestedUrl;
+    // https://fetch.spec.whatwg.org/#fetch-timing-info
+    // This class is using timingInfo assuming it's already validated.
+    // The spec doesn't say to validate it in the class construction.
+    this[kTimingInfo] = timingInfo;
+    this[kCacheMode] = cacheMode;
+  }, [], PerformanceResourceTiming);
 }
 
 // https://w3c.github.io/resource-timing/#dfn-mark-resource-timing
@@ -165,7 +213,7 @@ function markResourceTiming(
     cacheMode === '' || cacheMode === 'local',
     'cache must be an empty string or \'local\'',
   );
-  const resource = new InternalPerformanceResourceTiming(
+  const resource = createPerformanceResourceTiming(
     requestedUrl,
     initiatorType,
     timingInfo,
diff --git a/lib/internal/perf/timerify.js b/lib/internal/perf/timerify.js
index e4c97e70353977..7fd575bf682662 100644
--- a/lib/internal/perf/timerify.js
+++ b/lib/internal/perf/timerify.js
@@ -8,7 +8,7 @@ const {
   ReflectConstruct,
 } = primordials;
 
-const { InternalPerformanceEntry } = require('internal/perf/performance_entry');
+const { createNodePerformanceEntry } = require('internal/perf/performance_entry');
 const { now } = require('internal/perf/utils');
 
 const {
@@ -39,7 +39,7 @@ function processComplete(name, start, args, histogram) {
   if (histogram !== undefined)
     histogram.record(MathCeil(duration * 1e6));
   const entry =
-    new InternalPerformanceEntry(
+    createNodePerformanceEntry(
       name,
       'function',
       start,
diff --git a/lib/internal/perf/usertiming.js b/lib/internal/perf/usertiming.js
index c61be708829db1..4544c507752036 100644
--- a/lib/internal/perf/usertiming.js
+++ b/lib/internal/perf/usertiming.js
@@ -1,13 +1,17 @@
 'use strict';
 
 const {
+  ObjectDefineProperties,
+  ObjectSetPrototypeOf,
   SafeMap,
   SafeSet,
   SafeArrayIterator,
+  Symbol,
   SymbolToStringTag,
+  ReflectConstruct,
 } = primordials;
 
-const { InternalPerformanceEntry } = require('internal/perf/performance_entry');
+const { initPerformanceEntry, PerformanceEntry } = require('internal/perf/performance_entry');
 const { now } = require('internal/perf/utils');
 const { enqueue, bufferUserTiming } = require('internal/perf/observe');
 const nodeTiming = require('internal/perf/nodetiming');
@@ -16,11 +20,14 @@ const {
   validateNumber,
   validateObject,
   validateString,
+  validateInternalField,
 } = require('internal/validators');
 
 const {
   codes: {
+    ERR_ILLEGAL_CONSTRUCTOR,
     ERR_INVALID_ARG_VALUE,
+    ERR_MISSING_ARGS,
     ERR_PERFORMANCE_INVALID_TIMESTAMP,
     ERR_PERFORMANCE_MEASURE_INVALID_OPTIONS,
   },
@@ -30,8 +37,11 @@ const { structuredClone } = require('internal/structured_clone');
 const {
   kEmptyObject,
   lazyDOMException,
+  kEnumerableProperty,
 } = require('internal/util');
 
+const kDetail = Symbol('kDetail');
+
 const markTimings = new SafeMap();
 
 const nodeTimingReadOnlyAttributes = new SafeSet(new SafeArrayIterator([
@@ -59,12 +69,15 @@ function getMark(name) {
   return ts;
 }
 
-class PerformanceMark extends InternalPerformanceEntry {
-  constructor(name, options) {
+class PerformanceMark {
+  constructor(name, options = kEmptyObject) {
+    if (arguments.length === 0) {
+      throw new ERR_MISSING_ARGS('name');
+    }
     name = `${name}`;
+    options ??= kEmptyObject;
     if (nodeTimingReadOnlyAttributes.has(name))
       throw new ERR_INVALID_ARG_VALUE('name', name);
-    options ??= kEmptyObject;
     validateObject(options, 'options');
     const startTime = options.startTime ?? now();
     validateNumber(startTime, 'startTime');
@@ -76,25 +89,61 @@ class PerformanceMark extends InternalPerformanceEntry {
     detail = detail != null ?
       structuredClone(detail) :
       null;
-    super(name, 'mark', startTime, 0, detail);
+    initPerformanceEntry(this, name, 'mark', startTime, 0);
+    this[kDetail] = detail;
+  }
+
+  get detail() {
+    validateInternalField(this, kDetail, 'PerformanceMark');
+    return this[kDetail];
   }
 
   get [SymbolToStringTag]() {
     return 'PerformanceMark';
   }
+
+  toJSON() {
+    return {
+      name: this.name,
+      entryType: this.entryType,
+      startTime: this.startTime,
+      duration: this.duration,
+      detail: this[kDetail],
+    };
+  }
 }
+ObjectSetPrototypeOf(PerformanceMark, PerformanceEntry);
+ObjectSetPrototypeOf(PerformanceMark.prototype, PerformanceEntry.prototype);
+ObjectDefineProperties(PerformanceMark.prototype, {
+  detail: kEnumerableProperty,
+});
+
+class PerformanceMeasure extends PerformanceEntry {
+  constructor() {
+    throw new ERR_ILLEGAL_CONSTRUCTOR();
+  }
 
-class PerformanceMeasure extends InternalPerformanceEntry {
-  constructor(name, start, duration, detail) {
-    super(name, 'measure', start, duration, detail);
+  get detail() {
+    validateInternalField(this, kDetail, 'PerformanceMeasure');
+    return this[kDetail];
   }
 
   get [SymbolToStringTag]() {
     return 'PerformanceMeasure';
   }
 }
+ObjectDefineProperties(PerformanceMeasure.prototype, {
+  detail: kEnumerableProperty,
+});
+
+function createPerformanceMeasure(name, start, duration, detail) {
+  return ReflectConstruct(function PerformanceMeasure() {
+    initPerformanceEntry(this, name, 'measure', start, duration);
+    this[kDetail] = detail;
+  }, [], PerformanceMeasure);
+}
 
-function mark(name, options = kEmptyObject) {
+function mark(name, options) {
   const mark = new PerformanceMark(name, options);
   enqueue(mark);
   bufferUserTiming(mark);
@@ -160,7 +209,7 @@ function measure(name, startOrMeasureOptions, endMark) {
   } = calculateStartDuration(startOrMeasureOptions, endMark);
   let detail = startOrMeasureOptions?.detail;
   detail = detail != null ? structuredClone(detail) : null;
-  const measure = new PerformanceMeasure(name, start, duration, detail);
+  const measure = createPerformanceMeasure(name, start, duration, detail);
   enqueue(measure);
   bufferUserTiming(measure);
   return measure;
diff --git a/lib/internal/perf/utils.js b/lib/internal/perf/utils.js
index bcc7e223b8c882..a92e177e4246e9 100644
--- a/lib/internal/perf/utils.js
+++ b/lib/internal/perf/utils.js
@@ -29,5 +29,5 @@ function refreshTimeOrigin() {
 module.exports = {
   now,
   getMilestoneTimestamp,
-  refreshTimeOrigin
+  refreshTimeOrigin,
 };
diff --git a/lib/internal/process/pre_execution.js b/lib/internal/process/pre_execution.js
index 23d4dbcf6cd8e1..10405852243afd 100644
--- a/lib/internal/process/pre_execution.js
+++ b/lib/internal/process/pre_execution.js
@@ -365,7 +365,6 @@ function setupTraceCategoryState() {
 }
 
 function setupPerfHooks() {
-  require('internal/perf/performance').refreshTimeOrigin();
   require('internal/perf/utils').refreshTimeOrigin();
 }
 
diff --git a/lib/internal/validators.js b/lib/internal/validators.js
index de8a8bb9b83b34..a192f9e6302ddb 100644
--- a/lib/internal/validators.js
+++ b/lib/internal/validators.js
@@ -418,6 +418,12 @@ function validateLinkHeaderValue(value, name) {
   }
 }
 
+const validateInternalField = hideStackFrames((object, fieldKey, className) => {
+  if (typeof object !== 'object' || object === null || !ObjectPrototypeHasOwnProperty(object, fieldKey)) {
+    throw new ERR_INVALID_ARG_TYPE('this', className, object);
+  }
+});
+
 module.exports = {
   isInt32,
   isUint32,
@@ -440,5 +446,6 @@ module.exports = {
   validateUndefined,
   validateUnion,
   validateAbortSignal,
-  validateLinkHeaderValue
+  validateLinkHeaderValue,
+  validateInternalField,
 };
diff --git a/test/common/wpt.js b/test/common/wpt.js
index 01f937fafce841..b3ec2b369b3dcc 100644
--- a/test/common/wpt.js
+++ b/test/common/wpt.js
@@ -298,7 +298,7 @@ class WPTRunner {
     this.resource = new ResourceLoader(path);
 
     this.flags = [];
-    this.dummyGlobalThisScript = null;
+    this.globalThisInitScripts = [];
     this.initScript = null;
 
     this.status = new StatusLoader(path);
@@ -340,17 +340,17 @@ class WPTRunner {
   }
 
   get fullInitScript() {
-    if (this.initScript === null && this.dummyGlobalThisScript === null) {
-      return null;
+    if (this.globalThisInitScripts.length === null) {
+      return this.initScript;
     }
 
+    const globalThisInitScript = this.globalThisInitScripts.join('\n\n//===\n');
+
     if (this.initScript === null) {
-      return this.dummyGlobalThisScript;
-    } else if (this.dummyGlobalThisScript === null) {
-      return this.initScript;
+      return globalThisInitScript;
     }
 
-    return `${this.dummyGlobalThisScript}\n\n//===\n${this.initScript}`;
+    return `${globalThisInitScript}\n\n//===\n${this.initScript}`;
   }
 
   /**
@@ -361,8 +361,9 @@ class WPTRunner {
   pretendGlobalThisAs(name) {
     switch (name) {
       case 'Window': {
-        this.dummyGlobalThisScript =
-          'global.Window = Object.getPrototypeOf(globalThis).constructor;';
+        this.globalThisInitScripts.push(
+          `global.Window = Object.getPrototypeOf(globalThis).constructor;
+          self.GLOBAL.isWorker = () => false;`);
         break;
       }
 
@@ -376,6 +377,36 @@ class WPTRunner {
     }
   }
 
+  brandCheckGlobalScopeAttribute(name) {
+    // TODO(legendecas): idlharness GlobalScope attribute receiver validation.
+    const script = `
+      const desc = Object.getOwnPropertyDescriptor(globalThis, '${name}');
+      function getter() {
+        // Mimic GlobalScope instance brand check.
+        if (this !== globalThis) {
+          throw new TypeError('Illegal invocation');
+        }
+        return desc.get();
+      }
+      Object.defineProperty(getter, 'name', { value: 'get ${name}' });
+
+      function setter(value) {
+        // Mimic GlobalScope instance brand check.
+        if (this !== globalThis) {
+          throw new TypeError('Illegal invocation');
+        }
+        desc.set(value);
+      }
+      Object.defineProperty(setter, 'name', { value: 'set ${name}' });
+
+      Object.defineProperty(globalThis, '${name}', {
+        get: getter,
+        set: setter,
+      });
+    `;
+    this.globalThisInitScripts.push(script);
+  }
+
   // TODO(joyeecheung): work with the upstream to port more tests in .html
   // to .js.
   async runJsTests() {
diff --git a/test/fixtures/wpt/README.md b/test/fixtures/wpt/README.md
index 63175ead2a9c2d..dd6136c16abe4f 100644
--- a/test/fixtures/wpt/README.md
+++ b/test/fixtures/wpt/README.md
@@ -21,8 +21,9 @@ Last update:
 - html/webappapis/microtask-queuing: https://github.com/web-platform-tests/wpt/tree/2c5c3c4c27/html/webappapis/microtask-queuing
 - html/webappapis/structured-clone: https://github.com/web-platform-tests/wpt/tree/47d3fb280c/html/webappapis/structured-clone
 - html/webappapis/timers: https://github.com/web-platform-tests/wpt/tree/5873f2d8f1/html/webappapis/timers
-- interfaces: https://github.com/web-platform-tests/wpt/tree/fc086c82d5/interfaces
+- interfaces: https://github.com/web-platform-tests/wpt/tree/df731dab88/interfaces
 - performance-timeline: https://github.com/web-platform-tests/wpt/tree/17ebc3aea0/performance-timeline
+- resource-timing: https://github.com/web-platform-tests/wpt/tree/22d38586d0/resource-timing
 - resources: https://github.com/web-platform-tests/wpt/tree/c5b428f15a/resources
 - streams: https://github.com/web-platform-tests/wpt/tree/9e5ef42bd3/streams
 - url: https://github.com/web-platform-tests/wpt/tree/0e5b126cd0/url
diff --git a/test/fixtures/wpt/interfaces/WebCryptoAPI.idl b/test/fixtures/wpt/interfaces/WebCryptoAPI.idl
index d7fce62d5b0003..0e68ea82f59443 100644
--- a/test/fixtures/wpt/interfaces/WebCryptoAPI.idl
+++ b/test/fixtures/wpt/interfaces/WebCryptoAPI.idl
@@ -11,6 +11,7 @@ partial interface mixin WindowOrWorkerGlobalScope {
 interface Crypto {
   [SecureContext] readonly attribute SubtleCrypto subtle;
   ArrayBufferView getRandomValues(ArrayBufferView array);
+  [SecureContext] DOMString randomUUID();
 };
 
 typedef (object or DOMString) AlgorithmIdentifier;
@@ -29,7 +30,7 @@ enum KeyType { "public", "private", "secret" };
 
 enum KeyUsage { "encrypt", "decrypt", "sign", "verify", "deriveKey", "deriveBits", "wrapKey", "unwrapKey" };
 
-[SecureContext,Exposed=(Window,Worker)]
+[SecureContext,Exposed=(Window,Worker),Serializable]
 interface CryptoKey {
   readonly attribute KeyType type;
   readonly attribute boolean extractable;
diff --git a/test/fixtures/wpt/interfaces/console.idl b/test/fixtures/wpt/interfaces/console.idl
index 7cd73a61764fc1..fdf1d0df978378 100644
--- a/test/fixtures/wpt/interfaces/console.idl
+++ b/test/fixtures/wpt/interfaces/console.idl
@@ -3,7 +3,7 @@
 // (https://github.com/w3c/webref)
 // Source: Console Standard (https://console.spec.whatwg.org/)
 
-[Exposed=(Window,Worker,Worklet)]
+[Exposed=*]
 namespace console { // but see namespace object requirements below
   // Logging
   undefined assert(optional boolean condition = false, any... data);
diff --git a/test/fixtures/wpt/interfaces/dom.idl b/test/fixtures/wpt/interfaces/dom.idl
index 4a57b2e1eb4bce..96acfc6a717fb2 100644
--- a/test/fixtures/wpt/interfaces/dom.idl
+++ b/test/fixtures/wpt/interfaces/dom.idl
@@ -3,7 +3,7 @@
 // (https://github.com/w3c/webref)
 // Source: DOM Standard (https://dom.spec.whatwg.org/)
 
-[Exposed=(Window,Worker,AudioWorklet)]
+[Exposed=*]
 interface Event {
   constructor(DOMString type, optional EventInit eventInitDict = {});
 
@@ -46,7 +46,7 @@ partial interface Window {
   [Replaceable] readonly attribute (Event or undefined) event; // legacy
 };
 
-[Exposed=(Window,Worker)]
+[Exposed=*]
 interface CustomEvent : Event {
   constructor(DOMString type, optional CustomEventInit eventInitDict = {});
 
@@ -59,7 +59,7 @@ dictionary CustomEventInit : EventInit {
   any detail = null;
 };
 
-[Exposed=(Window,Worker,AudioWorklet)]
+[Exposed=*]
 interface EventTarget {
   constructor();
 
@@ -77,25 +77,28 @@ dictionary EventListenerOptions {
 };
 
 dictionary AddEventListenerOptions : EventListenerOptions {
-  boolean passive = false;
+  boolean passive;
   boolean once = false;
   AbortSignal signal;
 };
 
-[Exposed=(Window,Worker)]
+[Exposed=*]
 interface AbortController {
   constructor();
 
   [SameObject] readonly attribute AbortSignal signal;
 
-  undefined abort();
+  undefined abort(optional any reason);
 };
 
-[Exposed=(Window,Worker)]
+[Exposed=*]
 interface AbortSignal : EventTarget {
-  [NewObject] static AbortSignal abort();
+  [NewObject] static AbortSignal abort(optional any reason);
+  [Exposed=(Window,Worker), NewObject] static AbortSignal timeout([EnforceRange] unsigned long long milliseconds);
 
   readonly attribute boolean aborted;
+  readonly attribute any reason;
+  undefined throwIfAborted();
 
   attribute EventHandler onabort;
 };
diff --git a/test/fixtures/wpt/interfaces/encoding.idl b/test/fixtures/wpt/interfaces/encoding.idl
index 7585cb3717c9aa..a8cbe4431a2dc7 100644
--- a/test/fixtures/wpt/interfaces/encoding.idl
+++ b/test/fixtures/wpt/interfaces/encoding.idl
@@ -18,7 +18,7 @@ dictionary TextDecodeOptions {
   boolean stream = false;
 };
 
-[Exposed=(Window,Worker)]
+[Exposed=*]
 interface TextDecoder {
   constructor(optional DOMString label = "utf-8", optional TextDecoderOptions options = {});
 
@@ -35,7 +35,7 @@ dictionary TextEncoderEncodeIntoResult {
   unsigned long long written;
 };
 
-[Exposed=(Window,Worker)]
+[Exposed=*]
 interface TextEncoder {
   constructor();
 
@@ -44,14 +44,14 @@ interface TextEncoder {
 };
 TextEncoder includes TextEncoderCommon;
 
-[Exposed=(Window,Worker)]
+[Exposed=*]
 interface TextDecoderStream {
   constructor(optional DOMString label = "utf-8", optional TextDecoderOptions options = {});
 };
 TextDecoderStream includes TextDecoderCommon;
 TextDecoderStream includes GenericTransformStream;
 
-[Exposed=(Window,Worker)]
+[Exposed=*]
 interface TextEncoderStream {
   constructor();
 };
diff --git a/test/fixtures/wpt/interfaces/hr-time.idl b/test/fixtures/wpt/interfaces/hr-time.idl
index 93537d64ad18d7..13aa109b6c764c 100644
--- a/test/fixtures/wpt/interfaces/hr-time.idl
+++ b/test/fixtures/wpt/interfaces/hr-time.idl
@@ -5,7 +5,9 @@
 
 typedef double DOMHighResTimeStamp;
 
-[Exposed=(Window,Worker)]
+typedef unsigned long long EpochTimeStamp;
+
+[Exposed=*]
 interface Performance : EventTarget {
     DOMHighResTimeStamp now();
     readonly attribute DOMHighResTimeStamp timeOrigin;
diff --git a/test/fixtures/wpt/interfaces/html.idl b/test/fixtures/wpt/interfaces/html.idl
index d878cba3367cc6..d9068b4ad1e550 100644
--- a/test/fixtures/wpt/interfaces/html.idl
+++ b/test/fixtures/wpt/interfaces/html.idl
@@ -43,6 +43,7 @@ interface DOMStringList {
 };
 
 enum DocumentReadyState { "loading", "interactive", "complete" };
+enum DocumentVisibilityState { "visible", "hidden" };
 typedef (HTMLScriptElement or SVGScriptElement) HTMLOrSVGScriptElement;
 
 [LegacyOverrideBuiltIns]
@@ -87,9 +88,12 @@ partial interface Document {
   boolean queryCommandState(DOMString commandId);
   boolean queryCommandSupported(DOMString commandId);
   DOMString queryCommandValue(DOMString commandId);
+  readonly attribute boolean hidden;
+  readonly attribute DocumentVisibilityState visibilityState;
 
   // special event handler IDL attributes that only apply to Document objects
   [LegacyLenientThis] attribute EventHandler onreadystatechange;
+  attribute EventHandler onvisibilitychange;
 
   // also has obsolete members
 };
@@ -111,7 +115,8 @@ interface HTMLElement : Element {
   [CEReactions] attribute DOMString dir;
 
   // user interaction
-  [CEReactions] attribute boolean hidden;
+  [CEReactions] attribute (boolean or unrestricted double or DOMString)? hidden;
+  [CEReactions] attribute boolean inert;
   undefined click();
   [CEReactions] attribute DOMString accessKey;
   readonly attribute DOMString accessKeyLabel;
@@ -187,7 +192,7 @@ interface HTMLLinkElement : HTMLElement {
   [CEReactions] attribute USVString href;
   [CEReactions] attribute DOMString? crossOrigin;
   [CEReactions] attribute DOMString rel;
-  [CEReactions] attribute DOMString as; // (default "")
+  [CEReactions] attribute DOMString as;
   [SameObject, PutForwards=value] readonly attribute DOMTokenList relList;
   [CEReactions] attribute DOMString media;
   [CEReactions] attribute DOMString integrity;
@@ -197,6 +202,7 @@ interface HTMLLinkElement : HTMLElement {
   [CEReactions] attribute USVString imageSrcset;
   [CEReactions] attribute DOMString imageSizes;
   [CEReactions] attribute DOMString referrerPolicy;
+  [SameObject, PutForwards=value] readonly attribute DOMTokenList blocking;
   [CEReactions] attribute boolean disabled;
 
   // also has obsolete members
@@ -210,6 +216,7 @@ interface HTMLMetaElement : HTMLElement {
   [CEReactions] attribute DOMString name;
   [CEReactions] attribute DOMString httpEquiv;
   [CEReactions] attribute DOMString content;
+  [CEReactions] attribute DOMString media;
 
   // also has obsolete members
 };
@@ -218,7 +225,9 @@ interface HTMLMetaElement : HTMLElement {
 interface HTMLStyleElement : HTMLElement {
   [HTMLConstructor] constructor();
 
+  attribute boolean disabled;
   [CEReactions] attribute DOMString media;
+  [SameObject, PutForwards=value] readonly attribute DOMTokenList blocking;
 
   // also has obsolete members
 };
@@ -487,16 +496,6 @@ interface HTMLObjectElement : HTMLElement {
   // also has obsolete members
 };
 
-[Exposed=Window]
-interface HTMLParamElement : HTMLElement {
-  [HTMLConstructor] constructor();
-
-  [CEReactions] attribute DOMString name;
-  [CEReactions] attribute DOMString value;
-
-  // also has obsolete members
-};
-
 [Exposed=Window]
 interface HTMLVideoElement : HTMLMediaElement {
   [HTMLConstructor] constructor();
@@ -928,6 +927,8 @@ interface HTMLInputElement : HTMLElement {
   undefined setRangeText(DOMString replacement, unsigned long start, unsigned long end, optional SelectionMode selectionMode = "preserve");
   undefined setSelectionRange(unsigned long start, unsigned long end, optional DOMString direction);
 
+  undefined showPicker();
+
   // also has obsolete members
 };
 
@@ -972,7 +973,7 @@ interface HTMLSelectElement : HTMLElement {
 
   [SameObject] readonly attribute HTMLOptionsCollection options;
   [CEReactions] attribute unsigned long length;
-  getter Element? item(unsigned long index);
+  getter HTMLOptionElement? item(unsigned long index);
   HTMLOptionElement? namedItem(DOMString name);
   [CEReactions] undefined add((HTMLOptionElement or HTMLOptGroupElement) element, optional (HTMLElement or long)? before = null);
   [CEReactions] undefined remove(); // ChildNode overload
@@ -1214,6 +1215,9 @@ interface HTMLScriptElement : HTMLElement {
   [CEReactions] attribute DOMString text;
   [CEReactions] attribute DOMString integrity;
   [CEReactions] attribute DOMString referrerPolicy;
+  [SameObject, PutForwards=value] readonly attribute DOMTokenList blocking;
+
+  static boolean supports(DOMString type);
 
   // also has obsolete members
 };
@@ -1239,7 +1243,7 @@ dictionary AssignedNodesOptions {
   boolean flatten = false;
 };
 
-typedef (CanvasRenderingContext2D or ImageBitmapRenderingContext or WebGLRenderingContext or WebGL2RenderingContext) RenderingContext;
+typedef (CanvasRenderingContext2D or ImageBitmapRenderingContext or WebGLRenderingContext or WebGL2RenderingContext or GPUCanvasContext) RenderingContext;
 
 [Exposed=Window]
 interface HTMLCanvasElement : HTMLElement {
@@ -1264,7 +1268,8 @@ typedef (HTMLOrSVGImageElement or
          HTMLVideoElement or
          HTMLCanvasElement or
          ImageBitmap or
-         OffscreenCanvas) CanvasImageSource;
+         OffscreenCanvas or
+         VideoFrame) CanvasImageSource;
 
 enum PredefinedColorSpace { "srgb", "display-p3" };
 
@@ -1274,6 +1279,7 @@ dictionary CanvasRenderingContext2DSettings {
   boolean alpha = true;
   boolean desynchronized = false;
   PredefinedColorSpace colorSpace = "srgb";
+  boolean willReadFrequently = false;
 };
 
 enum ImageSmoothingQuality { "low", "medium", "high" };
@@ -1307,6 +1313,7 @@ interface mixin CanvasState {
   undefined save(); // push state on state stack
   undefined restore(); // pop state stack and restore state
   undefined reset(); // reset the rendering context to its default state
+  boolean isContextLost(); // return whether context is lost
 };
 
 interface mixin CanvasTransform {
@@ -1326,7 +1333,7 @@ interface mixin CanvasTransform {
 interface mixin CanvasCompositing {
   // compositing
   attribute unrestricted double globalAlpha; // (default 1.0)
-  attribute DOMString globalCompositeOperation; // (default source-over)
+  attribute DOMString globalCompositeOperation; // (default "source-over")
 };
 
 interface mixin CanvasImageSmoothing {
@@ -1357,7 +1364,14 @@ interface mixin CanvasShadowStyles {
 
 interface mixin CanvasFilters {
   // filters
-  attribute DOMString filter; // (default "none")
+  attribute (DOMString or CanvasFilter) filter; // (default "none")
+};
+
+typedef record<DOMString, any> CanvasFilterInput;
+
+[Exposed=(Window,Worker,PaintWorklet)]
+interface CanvasFilter {
+  constructor(optional (CanvasFilterInput or sequence<CanvasFilterInput>) filters);
 };
 
 interface mixin CanvasRect {
@@ -1441,12 +1455,12 @@ interface mixin CanvasTextDrawingStyles {
   attribute CanvasTextAlign textAlign; // (default: "start")
   attribute CanvasTextBaseline textBaseline; // (default: "alphabetic")
   attribute CanvasDirection direction; // (default: "inherit")
-  attribute double textLetterSpacing; // (default: 0)
-  attribute double textWordSpacing; // (default: 0)
+  attribute DOMString letterSpacing; // (default: "0px")
   attribute CanvasFontKerning fontKerning; // (default: "auto")
   attribute CanvasFontStretch fontStretch; // (default: "normal")
   attribute CanvasFontVariantCaps fontVariantCaps; // (default: "normal")
-  attribute CanvasTextRendering textRendering; // (default: "normal")
+  attribute CanvasTextRendering textRendering; // (default: "auto")
+  attribute DOMString wordSpacing; // (default: "0px")
 };
 
 interface mixin CanvasPath {
@@ -1458,6 +1472,7 @@ interface mixin CanvasPath {
   undefined bezierCurveTo(unrestricted double cp1x, unrestricted double cp1y, unrestricted double cp2x, unrestricted double cp2y, unrestricted double x, unrestricted double y);
   undefined arcTo(unrestricted double x1, unrestricted double y1, unrestricted double x2, unrestricted double y2, unrestricted double radius);
   undefined rect(unrestricted double x, unrestricted double y, unrestricted double w, unrestricted double h);
+  undefined roundRect(unrestricted double x, unrestricted double y, unrestricted double w, unrestricted double h, optional (unrestricted double or DOMPointInit or sequence<(unrestricted double or DOMPointInit)>) radii = 0);
   undefined arc(unrestricted double x, unrestricted double y, unrestricted double radius, unrestricted double startAngle, unrestricted double endAngle, optional boolean counterclockwise = false);
   undefined ellipse(unrestricted double x, unrestricted double y, unrestricted double radiusX, unrestricted double radiusY, unrestricted double rotation, unrestricted double startAngle, unrestricted double endAngle, optional boolean counterclockwise = false);
 };
@@ -1527,14 +1542,14 @@ dictionary ImageBitmapRenderingContextSettings {
   boolean alpha = true;
 };
 
-typedef (OffscreenCanvasRenderingContext2D or ImageBitmapRenderingContext or WebGLRenderingContext or WebGL2RenderingContext) OffscreenRenderingContext;
+typedef (OffscreenCanvasRenderingContext2D or ImageBitmapRenderingContext or WebGLRenderingContext or WebGL2RenderingContext or GPUCanvasContext) OffscreenRenderingContext;
 
 dictionary ImageEncodeOptions {
   DOMString type = "image/png";
   unrestricted double quality;
 };
 
-enum OffscreenRenderingContextId { "2d", "bitmaprenderer", "webgl", "webgl2" };
+enum OffscreenRenderingContextId { "2d", "bitmaprenderer", "webgl", "webgl2", "webgpu" };
 
 [Exposed=(Window,Worker), Transferable]
 interface OffscreenCanvas : EventTarget {
@@ -1546,6 +1561,9 @@ interface OffscreenCanvas : EventTarget {
   OffscreenRenderingContext? getContext(OffscreenRenderingContextId contextId, optional any options = null);
   ImageBitmap transferToImageBitmap();
   Promise<Blob> convertToBlob(optional ImageEncodeOptions options = {});
+
+  attribute EventHandler oncontextlost;
+  attribute EventHandler oncontextrestored;
 };
 
 [Exposed=(Window,Worker)]
@@ -1724,6 +1742,7 @@ interface Window : EventTarget {
 
   // the user agent
   readonly attribute Navigator navigator;
+  readonly attribute Navigator clientInformation; // legacy alias of .navigator
   readonly attribute boolean originAgentCluster;
 
   // user prompts
@@ -1741,7 +1760,7 @@ interface Window : EventTarget {
 Window includes GlobalEventHandlers;
 Window includes WindowEventHandlers;
 
-dictionary WindowPostMessageOptions : PostMessageOptions {
+dictionary WindowPostMessageOptions : StructuredSerializeOptions {
   USVString targetOrigin = "/";
 };
 
@@ -1823,7 +1842,7 @@ interface BeforeUnloadEvent : Event {
   attribute DOMString returnValue;
 };
 
-[Exposed=(Window,Worker)]
+[Exposed=*]
 interface ErrorEvent : Event {
   constructor(DOMString type, optional ErrorEventInit eventInitDict = {});
 
@@ -1839,10 +1858,10 @@ dictionary ErrorEventInit : EventInit {
   USVString filename = "";
   unsigned long lineno = 0;
   unsigned long colno = 0;
-  any error = null;
+  any error;
 };
 
-[Exposed=(Window,Worker)]
+[Exposed=*]
 interface PromiseRejectionEvent : Event {
   constructor(DOMString type, PromiseRejectionEventInit eventInitDict);
 
@@ -1870,6 +1889,8 @@ typedef OnBeforeUnloadEventHandlerNonNull? OnBeforeUnloadEventHandler;
 interface mixin GlobalEventHandlers {
   attribute EventHandler onabort;
   attribute EventHandler onauxclick;
+  attribute EventHandler onbeforeinput;
+  attribute EventHandler onbeforematch;
   attribute EventHandler onblur;
   attribute EventHandler oncancel;
   attribute EventHandler oncanplay;
@@ -1877,7 +1898,9 @@ interface mixin GlobalEventHandlers {
   attribute EventHandler onchange;
   attribute EventHandler onclick;
   attribute EventHandler onclose;
+  attribute EventHandler oncontextlost;
   attribute EventHandler oncontextmenu;
+  attribute EventHandler oncontextrestored;
   attribute EventHandler oncuechange;
   attribute EventHandler ondblclick;
   attribute EventHandler ondrag;
@@ -1968,15 +1991,17 @@ interface mixin WindowOrWorkerGlobalScope {
   readonly attribute boolean isSecureContext;
   readonly attribute boolean crossOriginIsolated;
 
+  undefined reportError(any e);
+
   // base64 utility methods
   DOMString btoa(DOMString data);
   ByteString atob(DOMString data);
 
   // timers
   long setTimeout(TimerHandler handler, optional long timeout = 0, any... arguments);
-  undefined clearTimeout(optional long handle = 0);
+  undefined clearTimeout(optional long id = 0);
   long setInterval(TimerHandler handler, optional long timeout = 0, any... arguments);
-  undefined clearInterval(optional long handle = 0);
+  undefined clearInterval(optional long id = 0);
 
   // microtask queuing
   undefined queueMicrotask(VoidFunction callback);
@@ -1984,6 +2009,9 @@ interface mixin WindowOrWorkerGlobalScope {
   // ImageBitmap
   Promise<ImageBitmap> createImageBitmap(ImageBitmapSource image, optional ImageBitmapOptions options = {});
   Promise<ImageBitmap> createImageBitmap(ImageBitmapSource image, long sx, long sy, long sw, long sh, optional ImageBitmapOptions options = {});
+
+  // structured cloning
+  any structuredClone(any value, optional StructuredSerializeOptions options = {});
 };
 Window includes WindowOrWorkerGlobalScope;
 WorkerGlobalScope includes WindowOrWorkerGlobalScope;
@@ -2050,6 +2078,49 @@ interface mixin NavigatorCookies {
   readonly attribute boolean cookieEnabled;
 };
 
+interface mixin NavigatorPlugins {
+  [SameObject] readonly attribute PluginArray plugins;
+  [SameObject] readonly attribute MimeTypeArray mimeTypes;
+  boolean javaEnabled();
+  readonly attribute boolean pdfViewerEnabled;
+};
+
+[Exposed=Window,
+ LegacyUnenumerableNamedProperties]
+interface PluginArray {
+  undefined refresh();
+  readonly attribute unsigned long length;
+  getter Plugin? item(unsigned long index);
+  getter Plugin? namedItem(DOMString name);
+};
+
+[Exposed=Window,
+ LegacyUnenumerableNamedProperties]
+interface MimeTypeArray {
+  readonly attribute unsigned long length;
+  getter MimeType? item(unsigned long index);
+  getter MimeType? namedItem(DOMString name);
+};
+
+[Exposed=Window,
+ LegacyUnenumerableNamedProperties]
+interface Plugin {
+  readonly attribute DOMString name;
+  readonly attribute DOMString description;
+  readonly attribute DOMString filename;
+  readonly attribute unsigned long length;
+  getter MimeType? item(unsigned long index);
+  getter MimeType? namedItem(DOMString name);
+};
+
+[Exposed=Window]
+interface MimeType {
+  readonly attribute DOMString type;
+  readonly attribute DOMString description;
+  readonly attribute DOMString suffixes;
+  readonly attribute Plugin enabledPlugin;
+};
+
 [Exposed=(Window,Worker), Serializable, Transferable]
 interface ImageBitmap {
   readonly attribute unsigned long width;
@@ -2131,53 +2202,6 @@ dictionary EventSourceInit {
   boolean withCredentials = false;
 };
 
-enum BinaryType { "blob", "arraybuffer" };
-[Exposed=(Window,Worker)]
-interface WebSocket : EventTarget {
-  constructor(USVString url, optional (DOMString or sequence<DOMString>) protocols = []);
-
-  readonly attribute USVString url;
-
-  // ready state
-  const unsigned short CONNECTING = 0;
-  const unsigned short OPEN = 1;
-  const unsigned short CLOSING = 2;
-  const unsigned short CLOSED = 3;
-  readonly attribute unsigned short readyState;
-  readonly attribute unsigned long long bufferedAmount;
-
-  // networking
-  attribute EventHandler onopen;
-  attribute EventHandler onerror;
-  attribute EventHandler onclose;
-  readonly attribute DOMString extensions;
-  readonly attribute DOMString protocol;
-  undefined close(optional [Clamp] unsigned short code, optional USVString reason);
-
-  // messaging
-  attribute EventHandler onmessage;
-  attribute BinaryType binaryType;
-  undefined send(USVString data);
-  undefined send(Blob data);
-  undefined send(ArrayBuffer data);
-  undefined send(ArrayBufferView data);
-};
-
-[Exposed=(Window,Worker)]
-interface CloseEvent : Event {
-  constructor(DOMString type, optional CloseEventInit eventInitDict = {});
-
-  readonly attribute boolean wasClean;
-  readonly attribute unsigned short code;
-  readonly attribute USVString reason;
-};
-
-dictionary CloseEventInit : EventInit {
-  boolean wasClean = false;
-  unsigned short code = 0;
-  USVString reason = "";
-};
-
 [Exposed=(Window,Worker)]
 interface MessageChannel {
   constructor();
@@ -2189,7 +2213,7 @@ interface MessageChannel {
 [Exposed=(Window,Worker,AudioWorklet), Transferable]
 interface MessagePort : EventTarget {
   undefined postMessage(any message, sequence<object> transfer);
-  undefined postMessage(any message, optional PostMessageOptions options = {});
+  undefined postMessage(any message, optional StructuredSerializeOptions options = {});
   undefined start();
   undefined close();
 
@@ -2198,7 +2222,7 @@ interface MessagePort : EventTarget {
   attribute EventHandler onmessageerror;
 };
 
-dictionary PostMessageOptions {
+dictionary StructuredSerializeOptions {
   sequence<object> transfer = [];
 };
 
@@ -2233,7 +2257,7 @@ interface DedicatedWorkerGlobalScope : WorkerGlobalScope {
   [Replaceable] readonly attribute DOMString name;
 
   undefined postMessage(any message, sequence<object> transfer);
-  undefined postMessage(any message, optional PostMessageOptions options = {});
+  undefined postMessage(any message, optional StructuredSerializeOptions options = {});
 
   undefined close();
 
@@ -2261,7 +2285,7 @@ interface Worker : EventTarget {
   undefined terminate();
 
   undefined postMessage(any message, sequence<object> transfer);
-  undefined postMessage(any message, optional PostMessageOptions options = {});
+  undefined postMessage(any message, optional StructuredSerializeOptions options = {});
   attribute EventHandler onmessage;
   attribute EventHandler onmessageerror;
 };
@@ -2560,7 +2584,12 @@ partial interface HTMLParagraphElement {
   [CEReactions] attribute DOMString align;
 };
 
-partial interface HTMLParamElement {
+[Exposed=Window]
+interface HTMLParamElement : HTMLElement {
+  [HTMLConstructor] constructor();
+
+  [CEReactions] attribute DOMString name;
+  [CEReactions] attribute DOMString value;
   [CEReactions] attribute DOMString type;
   [CEReactions] attribute DOMString valueType;
 };
@@ -2656,42 +2685,3 @@ interface External {
   undefined AddSearchProvider();
   undefined IsSearchProviderInstalled();
 };
-
-interface mixin NavigatorPlugins {
-  [SameObject] readonly attribute PluginArray plugins;
-  [SameObject] readonly attribute MimeTypeArray mimeTypes;
-  boolean javaEnabled();
-};
-
-[Exposed=Window]
-interface PluginArray {
-  undefined refresh();
-  readonly attribute unsigned long length;
-  getter object? item(unsigned long index);
-  object? namedItem(DOMString name);
-};
-
-[Exposed=Window]
-interface MimeTypeArray {
-  readonly attribute unsigned long length;
-  getter object? item(unsigned long index);
-  object? namedItem(DOMString name);
-};
-
-[Exposed=Window]
-interface Plugin {
-  readonly attribute undefined name;
-  readonly attribute undefined description;
-  readonly attribute undefined filename;
-  readonly attribute undefined length;
-  getter undefined item(unsigned long index);
-  undefined namedItem(DOMString name);
-};
-
-[Exposed=Window]
-interface MimeType {
-  readonly attribute undefined type;
-  readonly attribute undefined description;
-  readonly attribute undefined suffixes;
-  readonly attribute undefined enabledPlugin;
-};
diff --git a/test/fixtures/wpt/interfaces/performance-timeline.idl b/test/fixtures/wpt/interfaces/performance-timeline.idl
index d3a5a278055eba..9f6cc5e2e902dc 100644
--- a/test/fixtures/wpt/interfaces/performance-timeline.idl
+++ b/test/fixtures/wpt/interfaces/performance-timeline.idl
@@ -10,7 +10,7 @@ partial interface Performance {
 };
 typedef sequence<PerformanceEntry> PerformanceEntryList;
 
-[Exposed=(Window,Worker)]
+[Exposed=*]
 interface PerformanceEntry {
   readonly    attribute DOMString           name;
   readonly    attribute DOMString           entryType;
@@ -22,7 +22,7 @@ interface PerformanceEntry {
 callback PerformanceObserverCallback = undefined (PerformanceObserverEntryList entries,
                                              PerformanceObserver observer,
                                              optional PerformanceObserverCallbackOptions options = {});
-[Exposed=(Window,Worker)]
+[Exposed=*]
 interface PerformanceObserver {
   constructor(PerformanceObserverCallback callback);
   undefined observe (optional PerformanceObserverInit options = {});
@@ -41,7 +41,7 @@ dictionary PerformanceObserverInit {
   boolean buffered;
 };
 
-[Exposed=(Window,Worker)]
+[Exposed=*]
 interface PerformanceObserverEntryList {
   PerformanceEntryList getEntries();
   PerformanceEntryList getEntriesByType (DOMString type);
diff --git a/test/fixtures/wpt/interfaces/resource-timing.idl b/test/fixtures/wpt/interfaces/resource-timing.idl
new file mode 100644
index 00000000000000..235963b804bf9a
--- /dev/null
+++ b/test/fixtures/wpt/interfaces/resource-timing.idl
@@ -0,0 +1,32 @@
+// GENERATED CONTENT - DO NOT EDIT
+// Content was automatically extracted by Reffy into webref
+// (https://github.com/w3c/webref)
+// Source: Resource Timing Level 2 (https://w3c.github.io/resource-timing/)
+
+[Exposed=(Window,Worker)]
+interface PerformanceResourceTiming : PerformanceEntry {
+    readonly attribute DOMString initiatorType;
+    readonly attribute ByteString nextHopProtocol;
+    readonly attribute DOMHighResTimeStamp workerStart;
+    readonly attribute DOMHighResTimeStamp redirectStart;
+    readonly attribute DOMHighResTimeStamp redirectEnd;
+    readonly attribute DOMHighResTimeStamp fetchStart;
+    readonly attribute DOMHighResTimeStamp domainLookupStart;
+    readonly attribute DOMHighResTimeStamp domainLookupEnd;
+    readonly attribute DOMHighResTimeStamp connectStart;
+    readonly attribute DOMHighResTimeStamp connectEnd;
+    readonly attribute DOMHighResTimeStamp secureConnectionStart;
+    readonly attribute DOMHighResTimeStamp requestStart;
+    readonly attribute DOMHighResTimeStamp responseStart;
+    readonly attribute DOMHighResTimeStamp responseEnd;
+    readonly attribute unsigned long long  transferSize;
+    readonly attribute unsigned long long  encodedBodySize;
+    readonly attribute unsigned long long  decodedBodySize;
+    [Default] object toJSON();
+};
+
+partial interface Performance {
+  undefined clearResourceTimings ();
+  undefined setResourceTimingBufferSize (unsigned long maxSize);
+  attribute EventHandler onresourcetimingbufferfull;
+};
diff --git a/test/fixtures/wpt/interfaces/streams.idl b/test/fixtures/wpt/interfaces/streams.idl
index 99c3a5dee91f69..fd5420f16a0967 100644
--- a/test/fixtures/wpt/interfaces/streams.idl
+++ b/test/fixtures/wpt/interfaces/streams.idl
@@ -3,7 +3,7 @@
 // (https://github.com/w3c/webref)
 // Source: Streams Standard (https://streams.spec.whatwg.org/)
 
-[Exposed=(Window,Worker,Worklet), Transferable]
+[Exposed=*, Transferable]
 interface ReadableStream {
   constructor(optional object underlyingSource, optional QueuingStrategy strategy = {});
 
@@ -64,35 +64,30 @@ interface mixin ReadableStreamGenericReader {
   Promise<undefined> cancel(optional any reason);
 };
 
-[Exposed=(Window,Worker,Worklet)]
+[Exposed=*]
 interface ReadableStreamDefaultReader {
   constructor(ReadableStream stream);
 
-  Promise<ReadableStreamDefaultReadResult> read();
+  Promise<ReadableStreamReadResult> read();
   undefined releaseLock();
 };
 ReadableStreamDefaultReader includes ReadableStreamGenericReader;
 
-dictionary ReadableStreamDefaultReadResult {
- any value;
- boolean done;
+dictionary ReadableStreamReadResult {
+  any value;
+  boolean done;
 };
 
-[Exposed=(Window,Worker,Worklet)]
+[Exposed=*]
 interface ReadableStreamBYOBReader {
   constructor(ReadableStream stream);
 
-  Promise<ReadableStreamBYOBReadResult> read(ArrayBufferView view);
+  Promise<ReadableStreamReadResult> read(ArrayBufferView view);
   undefined releaseLock();
 };
 ReadableStreamBYOBReader includes ReadableStreamGenericReader;
 
-dictionary ReadableStreamBYOBReadResult {
- ArrayBufferView value;
- boolean done;
-};
-
-[Exposed=(Window,Worker,Worklet)]
+[Exposed=*]
 interface ReadableStreamDefaultController {
   readonly attribute unrestricted double? desiredSize;
 
@@ -101,7 +96,7 @@ interface ReadableStreamDefaultController {
   undefined error(optional any e);
 };
 
-[Exposed=(Window,Worker,Worklet)]
+[Exposed=*]
 interface ReadableByteStreamController {
   readonly attribute ReadableStreamBYOBRequest? byobRequest;
   readonly attribute unrestricted double? desiredSize;
@@ -111,7 +106,7 @@ interface ReadableByteStreamController {
   undefined error(optional any e);
 };
 
-[Exposed=(Window,Worker,Worklet)]
+[Exposed=*]
 interface ReadableStreamBYOBRequest {
   readonly attribute ArrayBufferView? view;
 
@@ -119,7 +114,7 @@ interface ReadableStreamBYOBRequest {
   undefined respondWithNewView(ArrayBufferView view);
 };
 
-[Exposed=(Window,Worker,Worklet), Transferable]
+[Exposed=*, Transferable]
 interface WritableStream {
   constructor(optional object underlyingSink, optional QueuingStrategy strategy = {});
 
@@ -143,7 +138,7 @@ callback UnderlyingSinkWriteCallback = Promise<undefined> (any chunk, WritableSt
 callback UnderlyingSinkCloseCallback = Promise<undefined> ();
 callback UnderlyingSinkAbortCallback = Promise<undefined> (optional any reason);
 
-[Exposed=(Window,Worker,Worklet)]
+[Exposed=*]
 interface WritableStreamDefaultWriter {
   constructor(WritableStream stream);
 
@@ -157,12 +152,13 @@ interface WritableStreamDefaultWriter {
   Promise<undefined> write(optional any chunk);
 };
 
-[Exposed=(Window,Worker,Worklet)]
+[Exposed=*]
 interface WritableStreamDefaultController {
+  readonly attribute AbortSignal signal;
   undefined error(optional any e);
 };
 
-[Exposed=(Window,Worker,Worklet), Transferable]
+[Exposed=*, Transferable]
 interface TransformStream {
   constructor(optional object transformer,
               optional QueuingStrategy writableStrategy = {},
@@ -184,7 +180,7 @@ callback TransformerStartCallback = any (TransformStreamDefaultController contro
 callback TransformerFlushCallback = Promise<undefined> (TransformStreamDefaultController controller);
 callback TransformerTransformCallback = Promise<undefined> (any chunk, TransformStreamDefaultController controller);
 
-[Exposed=(Window,Worker,Worklet)]
+[Exposed=*]
 interface TransformStreamDefaultController {
   readonly attribute unrestricted double? desiredSize;
 
@@ -198,13 +194,13 @@ dictionary QueuingStrategy {
   QueuingStrategySize size;
 };
 
-callback QueuingStrategySize = unrestricted double (optional any chunk);
+callback QueuingStrategySize = unrestricted double (any chunk);
 
 dictionary QueuingStrategyInit {
   required unrestricted double highWaterMark;
 };
 
-[Exposed=(Window,Worker,Worklet)]
+[Exposed=*]
 interface ByteLengthQueuingStrategy {
   constructor(QueuingStrategyInit init);
 
@@ -212,7 +208,7 @@ interface ByteLengthQueuingStrategy {
   readonly attribute Function size;
 };
 
-[Exposed=(Window,Worker,Worklet)]
+[Exposed=*]
 interface CountQueuingStrategy {
   constructor(QueuingStrategyInit init);
 
diff --git a/test/fixtures/wpt/interfaces/url.idl b/test/fixtures/wpt/interfaces/url.idl
index b00ab4b83bc60b..360c9adcfa1104 100644
--- a/test/fixtures/wpt/interfaces/url.idl
+++ b/test/fixtures/wpt/interfaces/url.idl
@@ -3,7 +3,7 @@
 // (https://github.com/w3c/webref)
 // Source: URL Standard (https://url.spec.whatwg.org/)
 
-[Exposed=(Window,Worker),
+[Exposed=*,
  LegacyWindowAlias=webkitURL]
 interface URL {
   constructor(USVString url, optional USVString base);
@@ -24,7 +24,7 @@ interface URL {
   USVString toJSON();
 };
 
-[Exposed=(Window,Worker)]
+[Exposed=*]
 interface URLSearchParams {
   constructor(optional (sequence<sequence<USVString>> or record<USVString, USVString> or USVString) init = "");
 
diff --git a/test/fixtures/wpt/interfaces/user-timing.idl b/test/fixtures/wpt/interfaces/user-timing.idl
index 28ee8aac2b19a6..a0b8f94710ec33 100644
--- a/test/fixtures/wpt/interfaces/user-timing.idl
+++ b/test/fixtures/wpt/interfaces/user-timing.idl
@@ -22,13 +22,13 @@ partial interface Performance {
     undefined clearMeasures(optional DOMString measureName);
 };
 
-[Exposed=(Window,Worker)]
+[Exposed=*]
 interface PerformanceMark : PerformanceEntry {
   constructor(DOMString markName, optional PerformanceMarkOptions markOptions = {});
   readonly attribute any detail;
 };
 
-[Exposed=(Window,Worker)]
+[Exposed=*]
 interface PerformanceMeasure : PerformanceEntry {
   readonly attribute any detail;
 };
diff --git a/test/fixtures/wpt/interfaces/webidl.idl b/test/fixtures/wpt/interfaces/webidl.idl
new file mode 100644
index 00000000000000..43748c5ac4c889
--- /dev/null
+++ b/test/fixtures/wpt/interfaces/webidl.idl
@@ -0,0 +1,50 @@
+// GENERATED CONTENT - DO NOT EDIT
+// Content was automatically extracted by Reffy into webref
+// (https://github.com/w3c/webref)
+// Source: Web IDL Standard (https://webidl.spec.whatwg.org/)
+
+typedef (Int8Array or Int16Array or Int32Array or
+         Uint8Array or Uint16Array or Uint32Array or Uint8ClampedArray or
+         BigInt64Array or BigUint64Array or
+         Float32Array or Float64Array or DataView) ArrayBufferView;
+
+typedef (ArrayBufferView or ArrayBuffer) BufferSource;
+[Exposed=(Window,Worker),
+ Serializable]
+interface DOMException { // but see below note about ECMAScript binding
+  constructor(optional DOMString message = "", optional DOMString name = "Error");
+  readonly attribute DOMString name;
+  readonly attribute DOMString message;
+  readonly attribute unsigned short code;
+
+  const unsigned short INDEX_SIZE_ERR = 1;
+  const unsigned short DOMSTRING_SIZE_ERR = 2;
+  const unsigned short HIERARCHY_REQUEST_ERR = 3;
+  const unsigned short WRONG_DOCUMENT_ERR = 4;
+  const unsigned short INVALID_CHARACTER_ERR = 5;
+  const unsigned short NO_DATA_ALLOWED_ERR = 6;
+  const unsigned short NO_MODIFICATION_ALLOWED_ERR = 7;
+  const unsigned short NOT_FOUND_ERR = 8;
+  const unsigned short NOT_SUPPORTED_ERR = 9;
+  const unsigned short INUSE_ATTRIBUTE_ERR = 10;
+  const unsigned short INVALID_STATE_ERR = 11;
+  const unsigned short SYNTAX_ERR = 12;
+  const unsigned short INVALID_MODIFICATION_ERR = 13;
+  const unsigned short NAMESPACE_ERR = 14;
+  const unsigned short INVALID_ACCESS_ERR = 15;
+  const unsigned short VALIDATION_ERR = 16;
+  const unsigned short TYPE_MISMATCH_ERR = 17;
+  const unsigned short SECURITY_ERR = 18;
+  const unsigned short NETWORK_ERR = 19;
+  const unsigned short ABORT_ERR = 20;
+  const unsigned short URL_MISMATCH_ERR = 21;
+  const unsigned short QUOTA_EXCEEDED_ERR = 22;
+  const unsigned short TIMEOUT_ERR = 23;
+  const unsigned short INVALID_NODE_TYPE_ERR = 24;
+  const unsigned short DATA_CLONE_ERR = 25;
+};
+
+callback Function = any (any... arguments);
+callback VoidFunction = undefined ();
+
+typedef unsigned long long DOMTimeStamp;
diff --git a/test/fixtures/wpt/resource-timing/304-response-recorded.html b/test/fixtures/wpt/resource-timing/304-response-recorded.html
new file mode 100644
index 00000000000000..9e1bb3045cd548
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/304-response-recorded.html
@@ -0,0 +1,53 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing - cached resources generate performance entries</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help"
+  href="https://www.w3.org/TR/resource-timing-2/#resources-included-in-the-performanceresourcetiming-interface"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/entry-invariants.js"></script>
+<script src="resources/resource-loaders.js"></script>
+</head>
+<body>
+<h1>Description</h1>
+<p>This test validates that a 304 Not Modified resource appears in the
+Performance Timeline.</p>
+<script>
+// Need to fetch the same resource twice; the first will get a 200 response but
+// the second request should be cached and get a 304.
+promise_test(async () => {
+  performance.clearResourceTimings();
+
+  const unique = Math.random();
+  const path = `resources/fake_responses.py?tag=${unique}`;
+
+  await load.xhr_sync(path);
+  await load.xhr_sync(path, {"If-None-Match": `${unique}`});
+  const entries = await new Promise(resolve => {
+    const accumulator = [];
+    new PerformanceObserver(entry_list => {
+      entry_list.getEntries().forEach(entry => {
+        accumulator.push(entry);
+      });
+      if (accumulator.length >= 2) {
+        resolve(accumulator);
+      }
+    }).observe({'type': 'resource', 'buffered': true});
+  });
+
+
+  if (entries.length != 2) {
+    throw new Error(`Expecting 2 but got ${entries.length} entries`);
+  }
+
+  assert_equals(entries[0].name, entries[1].name,
+    "Both entries should have the same name");
+  invariants.assert_tao_pass_no_redirect_http(entries[0]);
+  invariants.assert_tao_pass_304_not_modified_http(entries[1]);
+}, "304 responses should still show up in the PerformanceTimeline");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/CodingConventions.md b/test/fixtures/wpt/resource-timing/CodingConventions.md
new file mode 100644
index 00000000000000..39b8d13435ef49
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/CodingConventions.md
@@ -0,0 +1,77 @@
+For [Resource Timing][1] tests, we want to have a consistent and clear coding
+style. The goals of this style are to:
+*   Make it easier for new contributors to find their way around
+*   Help improve readability and maintainability
+*   Help us understand which parts of the spec are tested or not
+Lots of the following rules are arbitrary but the value is realized in
+consistency instead of adhering to the 'perfect' style.
+
+We want the test suite to be navigable. Developers should be able to easily
+find the file or test that is relevant to their work.
+*   Tests should be arranged in files according to which piece of the spec they
+    test
+*   Files should be named using a consistent pattern
+*   HTML files should include useful meta tags
+    *   `<title>` for controlling labels in results pages
+    *   `<link rel="help">` to point at the relevant piece of the spec
+
+We want the test suite to run consistently. Flaky tests are counterproductive.
+*   Prefer `promise_test` to `async_test`
+    *   Note that there’s [still potential for some concurrency][2]; use
+        `add_cleanup()` if needed
+
+We want the tests to be readable. Tests should be written in a modern style
+with recurring patterns.
+*   80 character line limits where we can
+*   Consistent use of anonymous functions
+    *   prefer
+        ```
+        const func1 = param1 => {
+          body();
+        }
+        const func2 = (param1, param2) => {
+          body();
+        }
+        fn(param => {
+            body();
+        });
+        ```
+
+        over
+
+        ```
+        function func1(param1) {
+          body();
+        }
+        function func2(param1, param2) {
+          body();
+        }
+        fn(function(param) {
+            body();
+        });
+        ```
+
+*   Prefer `const` (or, if needed, `let`) to `var`
+*   Contain use of ‘.sub’ in filenames to known helper utilities where possible
+    *   E.g. prefer use of get-host-info.sub.js to `{{host}}` or `{{ports[0]}}`
+        expressions
+*   Avoid use of webperftestharness[extension].js as it’s a layer of cognitive
+    overhead between test content and test intent
+    *   Helper .js files are still encouraged where it makes sense but we want
+        to avoid a testing framework that is specific to Resource Timing (or
+        web performance APIs, in general).
+*   Prefer [`fetch_tests_from_window`][3] to collect test results from embedded
+    iframes instead of hand-rolled `postMessage` approaches
+*   Use the [`assert_*`][4] family of functions to check conformance to the spec
+    but throw exceptions explicitly when the test itself is broken.
+    *    A failed assert indicates "the implementation doesn't conform to the
+         spec"
+    *    Other uncaught exceptions indicate "the test case itself has a bug"
+*   Where possible, we want tests to be scalable - adding another test case
+    should be as simple as calling the tests with new parameters, rather than
+    copying an existing test and modifying it.
+
+[1]: https://www.w3.org/TR/resource-timing-2/
+[2]: https://web-platform-tests.org/writing-tests/testharness-api.html#promise-tests
+[3]: https://web-platform-tests.org/writing-tests/testharness-api.html#consolidating-tests-from-other-documents
+[4]: https://web-platform-tests.org/writing-tests/testharness-api.html#list-of-assertions
diff --git a/test/fixtures/wpt/resource-timing/META.yml b/test/fixtures/wpt/resource-timing/META.yml
new file mode 100644
index 00000000000000..662c42cb664219
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/META.yml
@@ -0,0 +1,6 @@
+spec: https://w3c.github.io/resource-timing/
+suggested_reviewers:
+  - plehegar
+  - zqzhang
+  - igrigorik
+  - yoavweiss
diff --git a/test/fixtures/wpt/resource-timing/SO-XO-SO-redirect-chain-tao.https.html b/test/fixtures/wpt/resource-timing/SO-XO-SO-redirect-chain-tao.https.html
new file mode 100644
index 00000000000000..e6568910e4fe7b
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/SO-XO-SO-redirect-chain-tao.https.html
@@ -0,0 +1,64 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>This test validates resource timing information for a same-origin=>cross-origin=>same-origin redirect chain without Timing-Allow-Origin.</title>
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#sec-cross-origin-resources"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<script src="resources/resource-loaders.js"></script>
+<script src="resources/entry-invariants.js"></script>
+</head>
+<body>
+<script>
+const {HTTPS_REMOTE_ORIGIN} = get_host_info();
+const SAME_ORIGIN = location.origin;
+// Same-Origin => Cross-Origin => Same-Origin => Same-Origin redirect chain
+let destUrl = `${SAME_ORIGIN}/resource-timing/resources/multi_redirect.py?`;
+destUrl += `page_origin=${SAME_ORIGIN}`;
+destUrl += `&cross_origin=${HTTPS_REMOTE_ORIGIN}`;
+destUrl += `&final_resource=/resource-timing/resources/blank_page_green.htm`;
+
+// No TAO in the redirect chain
+attribute_test(
+  load.iframe, destUrl,
+  invariants.assert_cross_origin_redirected_resource,
+  "Verify that cross origin resources' timings are not exposed when " +
+  "same-origin=>cross-origin=>same-origin redirects have no " +
+  "`Timing-Allow-Origin:` headers.");
+
+// Partial TAO in the redirect chain
+destUrl += '&tao_steps=2';
+attribute_test(
+  load.iframe, destUrl,
+  invariants.assert_cross_origin_redirected_resource,
+  "Verify that cross origin resources' timings are not exposed when " +
+  "same-origin=>cross-origin=>same-origin redirects have " +
+  "`Timing-Allow-Origin:` headers only on some of the responses.");
+
+// Cross-origin => Cross-Origin => Same-Origin => Same-Origin redirect chain.
+destUrl = `${HTTPS_REMOTE_ORIGIN}/resource-timing/resources/multi_redirect.py?`;
+destUrl += `page_origin=${SAME_ORIGIN}`;
+destUrl += `&cross_origin=${HTTPS_REMOTE_ORIGIN}`;
+destUrl += `&final_resource=/resource-timing/resources/blue-with-tao.png`;
+destUrl += `&tao_steps=3`;
+
+// Full redirect chain with `TAO: *`.
+attribute_test(
+  load.image, destUrl,
+  invariants.assert_tao_enabled_cross_origin_redirected_resource,
+  "Verify that cross origin resources' timings are exposed when cross-origin " +
+  "redirects have `Timing-Allow-Origin: *` headers");
+
+// TAO with a specific origin
+destUrl += `&tao_value=${SAME_ORIGIN}`;
+attribute_test(
+  load.image, destUrl,
+  invariants.assert_cross_origin_redirected_resource,
+  "Verify that cross origin resources' timings are not exposed when " +
+  "same-origin=>cross-origin=>same-origin redirects have " +
+  "`Timing-Allow-Origin:` headers with a specific origin.");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/TAO-match.html b/test/fixtures/wpt/resource-timing/TAO-match.html
new file mode 100644
index 00000000000000..dc0e2f744347b2
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/TAO-match.html
@@ -0,0 +1,82 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing TAO tests</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help"
+      href="https://www.w3.org/TR/resource-timing-2/#timing-allow-origin"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<script src="/common/custom-cors-response.js"></script>
+<script src="resources/entry-invariants.js"></script>
+<script src="resources/resource-loaders.js"></script>
+<script src="resources/tao-response.js"></script>
+<body>
+<script>
+const {ORIGIN, REMOTE_ORIGIN} = get_host_info();
+
+const run_test = (loader, resource_type) => {
+  attribute_test(loader, remote_tao_response(ORIGIN),
+    invariants.assert_tao_pass_no_redirect_http,
+    `The timing allow check algorithm will pass when the Timing-Allow-Origin ` +
+    `header value contains only the origin. (${resource_type})`);
+
+  attribute_test(loader, remote_tao_response('*'),
+    invariants.assert_tao_pass_no_redirect_http,
+    `The timing allow check algorithm will pass when the Timing-Allow-Origin ` +
+    `header value contains only a wildcard. (${resource_type})`);
+
+  attribute_test(loader, remote_tao_response(`${ORIGIN},fake`),
+    invariants.assert_tao_pass_no_redirect_http,
+    `The timing allow check algorithm will pass when the Timing-Allow-Origin ` +
+    `header value list contains a case-sensitive match. (${resource_type})`);
+
+  attribute_test(loader, remote_tao_response(`${ORIGIN},*`),
+    invariants.assert_tao_pass_no_redirect_http,
+    `The timing allow check algorithm will pass when the Timing-Allow-Origin ` +
+    `header value list contains the origin and a wildcard. (${resource_type})`);
+
+  attribute_test(loader, remote_tao_response('fake,*'),
+    invariants.assert_tao_pass_no_redirect_http,
+    `The timing allow check algorithm will pass when the Timing-Allow-Origin ` +
+    `header value list contains a wildcard. (${resource_type})`);
+
+  attribute_test(loader, remote_tao_response('null'),
+    invariants.assert_tao_failure_resource,
+    `The timing allow check algorithm will fail when the Timing-Allow-Origin ` +
+    `header value list contains a null origin. (${resource_type})`);
+
+  attribute_test(loader, remote_tao_response('*,*'),
+    invariants.assert_tao_pass_no_redirect_http,
+    `The timing allow check algorithm will pass when the Timing-Allow-Origin ` +
+    `header value list contains multiple wildcards. (${resource_type})`);
+
+  attribute_test(loader, remote_tao_response(ORIGIN.toUpperCase()),
+    invariants.assert_tao_failure_resource,
+    `The timing allow check algorithm will fail when the Timing-Allow-Origin ` +
+    `header value contains only the uppercased origin. (${resource_type})`);
+
+  attribute_test(loader, remote_tao_response(`${ORIGIN} *`),
+    invariants.assert_tao_failure_resource,
+    `The timing allow check algorithm will fail when the Timing-Allow-Origin ` +
+    `header value contains the origin, a space, then a wildcard. ` +
+    `(${resource_type})`);
+
+  attribute_test(loader, custom_cors_response({}, REMOTE_ORIGIN),
+    invariants.assert_tao_failure_resource,
+    `The timing allow check algorithm will fail when the Timing-Allow-Origin ` +
+    `header is not present. (${resource_type})`);
+};
+
+run_test(load.font, "font");
+run_test(load.iframe, "iframe");
+run_test(load.image, "image");
+run_test(load.script, "script");
+run_test(load.stylesheet, "stylesheet");
+run_test(load.xhr_sync, "XMLHttpRequest");
+
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/TAO-port-mismatch-means-crossorigin.html b/test/fixtures/wpt/resource-timing/TAO-port-mismatch-means-crossorigin.html
new file mode 100644
index 00000000000000..f1218d17a0a44f
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/TAO-port-mismatch-means-crossorigin.html
@@ -0,0 +1,46 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>TAO - port mismatch must fail the check</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#sec-timing-allow-origin"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<script src="resources/entry-invariants.js"></script>
+<script>
+
+const {ORIGINAL_HOST, PORT, PORT2} = get_host_info();
+
+// The main page is being requested on the default port (PORT), while the
+// subresource will be requested on a separate port (PORT2). The response will
+// have a Timing-Allow-Origin header value with the second port so this page's
+// origin should not be a match.
+const port_mismatch_url = `${location.protocol}//${ORIGINAL_HOST}:${PORT2}` +
+                          `/resource-timing/resources/TAOResponse.py?` +
+                          `tao=origin_port_${PORT2}`;
+attribute_test(
+  fetch, port_mismatch_url, invariants.assert_tao_failure_resource,
+  "A port mismatch must fail the TAO check");
+
+// The same URL as above except the Timing-Allow-Origin header will have the
+// same port as this page's origin. Therefore, this page's origin will match
+// the Timing-Allow-Origin header's value. Therefore, the subresource's timings
+// must be exposed.
+const port_match_url = `${location.protocol}//${ORIGINAL_HOST}:${PORT2}` +
+                       `/resource-timing/resources/TAOResponse.py?` +
+                       `tao=origin_port_${PORT}`;
+attribute_test(
+  fetch, port_match_url, invariants.assert_tao_pass_no_redirect_http,
+  "An identical port must pass the TAO check");
+
+</script>
+</head>
+<body>
+<h1>Description</h1>
+<p>This test validates that for a cross origin resource with different ports,
+the timing allow check algorithm will fail when the value of
+Timing-Allow-Origin value has the right host but the wrong port in it.</p>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/buffer-full-add-after-full-event.html b/test/fixtures/wpt/resource-timing/buffer-full-add-after-full-event.html
new file mode 100644
index 00000000000000..43dc3d84fd3dd1
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/buffer-full-add-after-full-event.html
@@ -0,0 +1,27 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+<meta charset="utf-8">
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#dom-performance-setresourcetimingbuffersize">
+<title>This test validates that setResourceTimingBufferFull behaves appropriately when set to the current buffer level.</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/resource-loaders.js"></script>
+<script src="resources/buffer-full-utilities.js"></script>
+</head>
+<body>
+<script>
+promise_test(async t => {
+    await forceBufferFullEvent();
+    performance.clearResourceTimings();
+    return new Promise(resolve => {
+      new PerformanceObserver(t.step_func(() => {
+        assert_equals(performance.getEntriesByType('resource').length, 1,
+            'The entry should be available in the performance timeline!');
+        resolve();
+      })).observe({type: 'resource'});
+      load.script(scriptResources[2]);
+    });
+}, "Test that entry was added to the buffer after a buffer full event");
+</script>
diff --git a/test/fixtures/wpt/resource-timing/buffer-full-add-entries-during-callback-that-drop.html b/test/fixtures/wpt/resource-timing/buffer-full-add-entries-during-callback-that-drop.html
new file mode 100644
index 00000000000000..b00185c5b6c881
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/buffer-full-add-entries-during-callback-that-drop.html
@@ -0,0 +1,29 @@
+<!DOCTYPE HTML>
+<html>
+<head onload>
+<meta charset="utf-8" />
+<title>This test validates that synchronously adding entries in onresourcetimingbufferfull callback results in these entries being properly handled.</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#dom-performance-onresourcetimingbufferfull"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/resource-loaders.js"></script>
+<script src="resources/buffer-full-utilities.js"></script>
+</head>
+<body>
+<script>
+promise_test(async () => {
+    await fillUpTheBufferWithSingleResource();
+    performance.addEventListener('resourcetimingbufferfull', () => {
+        performance.setResourceTimingBufferSize(2);
+        // The sync entry is added to the secondary buffer, so will be the last one there and eventually dropped.
+        load.xhr_sync(scriptResources[2]);
+    });
+    // This resource overflows the entry buffer, and goes into the secondary buffer.
+    load.script(scriptResources[1]);
+    await bufferFullFirePromise;
+    checkEntries(2);
+}, "Test that entries synchronously added to the buffer during the callback are dropped");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/buffer-full-add-entries-during-callback.html b/test/fixtures/wpt/resource-timing/buffer-full-add-entries-during-callback.html
new file mode 100644
index 00000000000000..d5883d33d5d780
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/buffer-full-add-entries-during-callback.html
@@ -0,0 +1,28 @@
+<!DOCTYPE HTML>
+<html>
+<head onload>
+<meta charset="utf-8" />
+<title>This test validates that synchronously adding entries in onresourcetimingbufferfull callback results in these entries being properly handled.</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#dom-performance-onresourcetimingbufferfull"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/resource-loaders.js"></script>
+<script src="resources/buffer-full-utilities.js"></script>
+</head>
+<body>
+<script>
+promise_test(async () => {
+    await fillUpTheBufferWithSingleResource();
+    performance.addEventListener('resourcetimingbufferfull', () => {
+        performance.setResourceTimingBufferSize(3);
+        load.xhr_sync(scriptResources[2]);
+    });
+    // This resource overflows the entry buffer, and goes into the secondary buffer.
+    load.script(scriptResources[1]);
+    await bufferFullFirePromise;
+    checkEntries(3);
+}, "Test that entries synchronously added to the buffer during the callback don't get dropped if the buffer is increased");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/buffer-full-add-then-clear.html b/test/fixtures/wpt/resource-timing/buffer-full-add-then-clear.html
new file mode 100644
index 00000000000000..5617c30b8850d8
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/buffer-full-add-then-clear.html
@@ -0,0 +1,31 @@
+<!DOCTYPE HTML>
+<html>
+<head onload>
+<meta charset="utf-8" />
+<title>This test validates that synchronously adding entries in onresourcetimingbufferfull callback results in these entries being properly handled.</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#dom-performance-onresourcetimingbufferfull"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/resource-loaders.js"></script>
+<script src="resources/buffer-full-utilities.js"></script>
+</head>
+<body>
+<script>
+promise_test(async t => {
+    addAssertUnreachedBufferFull(t);
+    await fillUpTheBufferWithSingleResource('resources/empty.js?willbelost');
+    // These resources overflow the entry buffer, and go into the secondary buffer.
+    load.xhr_sync(scriptResources[0]);
+    load.xhr_sync(scriptResources[1]);
+    performance.clearResourceTimings();
+    performance.setResourceTimingBufferSize(3);
+    load.xhr_sync(scriptResources[2]);
+    const entriesAfterAddition = performance.getEntriesByType('resource');
+    await waitForNextTask();
+    checkEntries(3);
+    assert_equals(entriesAfterAddition.length, 0, "No entries should have been added to the primary buffer before the task to 'fire a buffer full event'.");
+}, "Test that if the buffer is cleared after entries were added to the secondary buffer, those entries make it into the primary one");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/buffer-full-decrease-buffer-during-callback.html b/test/fixtures/wpt/resource-timing/buffer-full-decrease-buffer-during-callback.html
new file mode 100644
index 00000000000000..3091fcf4269192
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/buffer-full-decrease-buffer-during-callback.html
@@ -0,0 +1,26 @@
+<!DOCTYPE HTML>
+<html>
+<head onload>
+<meta charset="utf-8" />
+<title>This test validates that decreasing the buffer size in onresourcetimingbufferfull callback does not result in extra entries being dropped.</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#dom-performance-onresourcetimingbufferfull"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/resource-loaders.js"></script>
+<script src="resources/buffer-full-utilities.js"></script>
+</head>
+<body>
+<script>
+promise_test(async () => {
+    performance.addEventListener('resourcetimingbufferfull', () => {
+        performance.setResourceTimingBufferSize(1);
+    });
+    await fillUpTheBufferWithTwoResources();
+    load.script(scriptResources[2]);
+    await bufferFullFirePromise;
+    checkEntries(2);
+}, "Test that decreasing the buffer limit during the callback does not drop entries");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/buffer-full-eventually.html b/test/fixtures/wpt/resource-timing/buffer-full-eventually.html
new file mode 100644
index 00000000000000..6e9d5db4839903
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/buffer-full-eventually.html
@@ -0,0 +1,31 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+<meta charset="utf-8" />
+<link rel="help"
+      href="http://www.w3.org/TR/resource-timing/#performanceresourcetiming"/>
+<title>This test validates that resource timing implementations have a finite
+       number of entries in their buffer.</title>
+<meta name="timeout" content="long">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<script>
+promise_test(t => {
+  return new Promise(resolve => {
+    let counter = 0;
+    performance.onresourcetimingbufferfull = resolve;
+    const loadImagesRecursively = () => {
+      // Load an image.
+      (new Image()).src = "resources/blue.png?" + counter;
+      ++counter;
+      // Yield to enable queueing an entry, then recursively load another image.
+      t.step_timeout(loadImagesRecursively, 0);
+    };
+    loadImagesRecursively();
+  });
+}, "Finite resource timing entries buffer size");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/buffer-full-increase-buffer-during-callback.html b/test/fixtures/wpt/resource-timing/buffer-full-increase-buffer-during-callback.html
new file mode 100644
index 00000000000000..dd12dd7afa9be1
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/buffer-full-increase-buffer-during-callback.html
@@ -0,0 +1,26 @@
+<!DOCTYPE HTML>
+<html>
+<head onload>
+<meta charset="utf-8" />
+<title>This test validates increasing the buffer size in onresourcetimingbufferfull callback of resource timing.</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#dom-performance-onresourcetimingbufferfull"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/resource-loaders.js"></script>
+<script src="resources/buffer-full-utilities.js"></script>
+</head>
+<body>
+<script>
+promise_test(async () => {
+    await fillUpTheBufferWithSingleResource();
+    performance.addEventListener('resourcetimingbufferfull', () => {
+        performance.setResourceTimingBufferSize(2);
+    });
+    await load.script(scriptResources[1]);
+    await bufferFullFirePromise;
+    checkEntries(2);
+}, "Test that increasing the buffer during the callback is enough for entries not to be dropped");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/buffer-full-inspect-buffer-during-callback.html b/test/fixtures/wpt/resource-timing/buffer-full-inspect-buffer-during-callback.html
new file mode 100644
index 00000000000000..d5cc8e6ecd8d11
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/buffer-full-inspect-buffer-during-callback.html
@@ -0,0 +1,30 @@
+<!DOCTYPE HTML>
+<html>
+<head onload>
+<meta charset="utf-8" />
+<title>This test validates the buffer doesn't contain more entries than it should inside onresourcetimingbufferfull callback.</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#dom-performance-setresourcetimingbuffersize"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/resource-loaders.js"></script>
+<script src="resources/buffer-full-utilities.js"></script>
+</head>
+<body>
+<script>
+promise_test(async t => {
+    performance.addEventListener('resourcetimingbufferfull', t.step_func(() => {
+        assert_equals(performance.getEntriesByType("resource").length, 1,
+            "resource timing buffer in resourcetimingbufferfull is the size of the limit");
+        load.xhr_sync(scriptResources[2]);
+        performance.setResourceTimingBufferSize(3);
+        assert_equals(performance.getEntriesByType("resource").length, 1,
+            "A sync request must not be added to the primary buffer just yet, because it is full");
+    }));
+    await forceBufferFullEvent();
+    await waitForNextTask();
+    checkEntries(3);
+}, "Test that entries in the secondary buffer are not exposed during the callback and before they are copied to the primary buffer");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/buffer-full-set-to-current-buffer.html b/test/fixtures/wpt/resource-timing/buffer-full-set-to-current-buffer.html
new file mode 100644
index 00000000000000..dc527b9a32f514
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/buffer-full-set-to-current-buffer.html
@@ -0,0 +1,34 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+<meta charset="utf-8">
+<title>This test validates that setResourceTimingBufferFull behaves appropriately when set to the current buffer level.</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#dom-performance-onresourcetimingbufferfull">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/resource-loaders.js"></script>
+<script src="resources/buffer-full-utilities.js"></script>
+</head>
+<body>
+<script>
+promise_test(async () => {
+    let result = '';
+    performance.addEventListener('resourcetimingbufferfull', () => {
+        result += 'Event Fired with '  +
+            performance.getEntriesByType('resource').length + ' entries.';
+        performance.clearResourceTimings();
+    });
+    result += 'Before adding entries. ';
+    await fillUpTheBufferWithTwoResources();
+    result += 'After adding entries. ';
+    load.script(scriptResources[2]);
+    await bufferFullFirePromise;
+    assert_equals(result, 'Before adding entries. After adding entries. Event Fired with 2 entries.');
+    const entries = performance.getEntriesByType('resource');
+    assert_equals(entries.length, 1,
+        'Number of entries in resource timing buffer is unexpected');
+    assert_true(entries[0].name.includes(scriptResources[2]),
+        'The entry must correspond to the last resource loaded.')
+}, "Test that adding entries and firing the buffer full event happen in the right order.");
+</script>
diff --git a/test/fixtures/wpt/resource-timing/buffer-full-store-and-clear-during-callback.html b/test/fixtures/wpt/resource-timing/buffer-full-store-and-clear-during-callback.html
new file mode 100644
index 00000000000000..3ea0577256c85b
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/buffer-full-store-and-clear-during-callback.html
@@ -0,0 +1,36 @@
+<!DOCTYPE HTML>
+<html>
+<head onload>
+<meta charset="utf-8" />
+<title>This test validates the behavior of read and clear operation in onresourcetimingbufferfull callback of resource timing.</title>
+<link rel="author" title="Intel" href="http://www.intel.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#dom-performance-onresourcetimingbufferfull"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/resource-loaders.js"></script>
+<script src="resources/buffer-full-utilities.js"></script>
+</head>
+<body>
+<script>
+promise_test(async () => {
+    await fillUpTheBufferWithSingleResource();
+    const entryBuffer = [];
+    performance.addEventListener('resourcetimingbufferfull', () => {
+      entryBuffer.push(...performance.getEntriesByType('resource'));
+      performance.clearResourceTimings();
+    });
+    load.script(scriptResources[1]);
+    await bufferFullFirePromise;
+    const entries = performance.getEntriesByType('resource');
+    assert_equals(entries.length, 1,
+        "Only the last entry should be stored in resource timing buffer since it's cleared once it overflows.");
+    assert_true(entries[0].name.includes(scriptResources[1]),
+        scriptResources[1]  + " is in the entries buffer");
+    assert_equals(entryBuffer.length, 1,
+        '1 resource timing entry should be moved to entryBuffer.');
+    assert_true(entryBuffer[0].name.includes(scriptResources[0]),
+        scriptResources[0] + ' is in the entryBuffer');
+}, "Test that entries overflowing the buffer trigger the buffer full event, can be stored, and make their way to the primary buffer after it's cleared in the buffer full event.");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/buffer-full-then-decreased.html b/test/fixtures/wpt/resource-timing/buffer-full-then-decreased.html
new file mode 100644
index 00000000000000..21912d978b294d
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/buffer-full-then-decreased.html
@@ -0,0 +1,29 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>This test validates that reducing the buffer size after entries were
+  queued does not drop those entries, nor does it call the
+  resourcetimingbufferfull event callback.</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help"
+ href="https://www.w3.org/TR/resource-timing-2/#dom-performance-onresourcetimingbufferfull"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/resource-loaders.js"></script>
+<script src="resources/buffer-full-utilities.js"></script>
+</head>
+<body>
+<script>
+promise_test(async t => {
+    addAssertUnreachedBufferFull(t);
+    await fillUpTheBufferWithTwoResources();
+    performance.setResourceTimingBufferSize(1);
+    await waitForNextTask();
+    checkEntries(2);
+}, "Test that if the buffer is reduced after entries were added to it, those" +
+   " entries don't get cleared, nor is the resourcetimingbufferfull event" +
+   " being called.");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/buffer-full-then-increased.html b/test/fixtures/wpt/resource-timing/buffer-full-then-increased.html
new file mode 100644
index 00000000000000..de517bf405c66e
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/buffer-full-then-increased.html
@@ -0,0 +1,28 @@
+<!DOCTYPE HTML>
+<html>
+<head onload>
+<meta charset="utf-8" />
+<title>This test validates that synchronously adding entries in onresourcetimingbufferfull callback results in these entries being properly handled.</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#dom-performance-onresourcetimingbufferfull"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/resource-loaders.js"></script>
+<script src="resources/buffer-full-utilities.js"></script>
+</head>
+<body>
+<script>
+promise_test(async t => {
+    addAssertUnreachedBufferFull(t);
+    await fillUpTheBufferWithSingleResource();
+    // These resources overflow the entry buffer, and go into the secondary buffer.
+    load.xhr_sync(scriptResources[1]);
+    load.xhr_sync(scriptResources[2]);
+    // Immediately increase the size: the bufferfull event should not be fired.
+    performance.setResourceTimingBufferSize(3);
+    await waitForNextTask();
+    checkEntries(3);
+}, "Test that overflowing the buffer and immediately increasing its limit does not trigger the resourcetimingbufferfull event");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/buffer-full-when-populate-entries.html b/test/fixtures/wpt/resource-timing/buffer-full-when-populate-entries.html
new file mode 100644
index 00000000000000..f4b1a2e7e7abba
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/buffer-full-when-populate-entries.html
@@ -0,0 +1,30 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>This test validates the functionality of onresourcetimingbufferfull in resource timing.</title>
+<link rel="author" title="Intel" href="http://www.intel.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#dom-performance-onresourcetimingbufferfull"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/resource-loaders.js"></script>
+<script src="resources/buffer-full-utilities.js"></script>
+</head>
+<body>
+<script>
+promise_test(async () => {
+    let bufferFullCount = 0;
+    performance.addEventListener('resourcetimingbufferfull', e => {
+        assert_equals(e.bubbles, false, "Event bubbles attribute is false");
+        bufferFullCount++;
+    });
+    await fillUpTheBufferWithTwoResources();
+    // Overflow the buffer
+    await load.script(scriptResources[2]);
+    await waitForNextTask();
+    checkEntries(2);
+    assert_equals(bufferFullCount, 1, 'onresourcetimingbufferfull should have been invoked once.');
+}, "Test that a buffer full event does not bubble and that resourcetimingbufferfull is called only once per overflow");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/buffered-flag.any.js b/test/fixtures/wpt/resource-timing/buffered-flag.any.js
new file mode 100644
index 00000000000000..b46fd00e69ddfc
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/buffered-flag.any.js
@@ -0,0 +1,18 @@
+async_test(t => {
+  performance.clearResourceTimings();
+  // First observer creates second in callback to ensure the entry has been dispatched by the time
+  // the second observer begins observing.
+  new PerformanceObserver(() => {
+    // Second observer requires 'buffered: true' to see an entry.
+    new PerformanceObserver(t.step_func_done(list => {
+      const entries = list.getEntries();
+      assert_equals(entries.length, 1, 'There should be 1 resource entry.');
+      assert_equals(entries[0].entryType, 'resource');
+      assert_greater_than(entries[0].startTime, 0);
+      assert_greater_than(entries[0].responseEnd, entries[0].startTime);
+      assert_greater_than(entries[0].duration, 0);
+      assert_true(entries[0].name.endsWith('resources/empty.js'));
+    })).observe({'type': 'resource', buffered: true});
+  }).observe({'entryTypes': ['resource']});
+  fetch('resources/empty.js');
+}, 'PerformanceObserver with buffered flag sees previous resource entries.');
diff --git a/test/fixtures/wpt/resource-timing/cached-image-gets-single-entry.html b/test/fixtures/wpt/resource-timing/cached-image-gets-single-entry.html
new file mode 100644
index 00000000000000..2d8c4e2e83944d
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/cached-image-gets-single-entry.html
@@ -0,0 +1,67 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing: test behavior for cached resources</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/observe-entry.js"></script>
+</head>
+<body>
+<h1>Description</h1>
+<p>Test that a reused resource only appears in the buffer once.</p>
+<script>
+// Need our own image loading helper because the one in resource-loaders.js
+// is desgined to always side-step the HTTP cache but this test relies on the
+// second request being resolved from the cache.
+const load_image = path => new Promise(resolve => {
+  const img = document.createElement('img');
+  img.onload = img.onerror = () => resolve();
+  img.src = path;
+  document.body.append(img);
+});
+
+promise_test(async () => {
+  const blue = "resources/blue.png";
+
+  // First request. Should appear in the timeline.
+  await load_image(blue + "?cacheable");
+
+  // Second request. Should not appear in the timeline.
+  await load_image(blue + "?cacheable");
+
+  // Third request. When this request shows up in the timeline, we know that, if
+  // the second request would generate an entry, that entry would have already
+  // shown up in the timeline. Without this, we'd need to guess at how long to
+  // wait which tends to be flaky.
+  await load_image(blue + "?avoid-cache");
+
+  const entries = await new Promise(resolve => {
+    const accumulator = [];
+    new PerformanceObserver(entry_list => {
+      entry_list.getEntries().forEach(entry => {
+        if (!entry.name.includes("blue.png")) {
+          // Ignore resources other than blue images.
+          return;
+        }
+        accumulator.push(entry);
+
+        // Once we see the 'canary' resource, we don't need to wait anymore.
+        if (entry.name.endsWith('avoid-cache')) {
+          resolve(accumulator);
+        }
+      });
+    }).observe({'type': 'resource', 'buffered': true});
+  });
+
+  assert_equals(entries.length, 2, "There must be exactly 2 entries in the " +
+    "Performance Timeline");
+  assert_true(entries[0].name.endsWith("blue.png?cacheable"));
+  assert_true(entries[1].name.endsWith("blue.png?avoid-cache"));
+}, "When a resource is resolved from cache, there must not be a " +
+  "corresponding entry in the Performance Timeline");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/clear-resource-timings.html b/test/fixtures/wpt/resource-timing/clear-resource-timings.html
new file mode 100644
index 00000000000000..7508f8432e66f5
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/clear-resource-timings.html
@@ -0,0 +1,22 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>This test validates the functionality of clearResourceTimings method
+in resource timing.</title>
+<link rel="author" title="Intel" href="http://www.intel.com/" />
+<link rel="help"
+ href="https://www.w3.org/TR/resource-timing-2/#dom-performance-clearresourcetimings">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+test(() => {
+  assert_equals(performance.getEntriesByType("resource").length, 2,
+                "Resource timing entries exist");
+  performance.clearResourceTimings();
+  assert_equals(performance.getEntriesByType("resource").length, 0,
+                "Resource timing entries are cleared");
+}, "Test that clearResourceTimings() clears the performance timeline buffer");
+</script>
+</head>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/connection-reuse.html b/test/fixtures/wpt/resource-timing/connection-reuse.html
new file mode 100644
index 00000000000000..a1bc927cfd3f2b
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/connection-reuse.html
@@ -0,0 +1,56 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing connection reuse</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#sec-performanceresourcetiming"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<script src="resources/entry-invariants.js"></script>
+<script src="resources/connection-reuse-test.js"></script>
+<script>
+  const {HTTPS_ORIGIN} = get_host_info();
+
+  // Fetches the given subresource a couple times with the same connection.
+  const http_path = "resources/fake_responses.py";
+  connection_reuse_test(http_path,
+    {
+      'on_200': invariants.assert_tao_pass_no_redirect_http,
+      'on_304': invariants.assert_tao_pass_304_not_modified_http,
+    }, "Reuse HTTP connection");
+
+  // Like above, but the subresource is fetched over HTTPS while this page is
+  // fetched over HTTP.
+  const https_url = `${HTTPS_ORIGIN}/resource-timing/${http_path}`;
+  connection_reuse_test(https_url,
+    {
+      'on_200': invariants.assert_tao_pass_no_redirect_https,
+      'on_304': invariants.assert_tao_pass_304_not_modified_https,
+    }, "Reuse HTTPS connection from HTTP page");
+
+  // Like the above mixed-content test but the final resource is behind an HTTP
+  // redirect response.
+  const redirect_path = (() => {
+    // The resource behind the redirect is the same fake_responses.py handler
+    // on the HTTPS origin. Pass it through encodeURIComponent so that it can
+    // be passed through a query-parameter.
+    const redirect_url = encodeURIComponent(https_url)
+    // The request is made to the HTTPS origin with a query parameter that will
+    // cause a 302 response.
+    return `${https_url}?redirect=${redirect_url}`;
+  })();
+  connection_reuse_test(redirect_path,
+    {
+      'on_200': invariants.assert_tao_enabled_cross_origin_redirected_resource,
+      'on_304': invariants.assert_tao_enabled_cross_origin_redirected_resource,
+    }, "Reuse HTTPS connection with redirects from an HTTP page");
+</script>
+</head>
+<body>
+<h1>Description</h1>
+<p>See <a href="resources/connection-reuse-test.js">the included test
+  script</a></p>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/connection-reuse.https.html b/test/fixtures/wpt/resource-timing/connection-reuse.https.html
new file mode 100644
index 00000000000000..3461eed47249df
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/connection-reuse.https.html
@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing connection reuse</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#sec-performanceresourcetiming"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/entry-invariants.js"></script>
+<script src="resources/connection-reuse-test.js"></script>
+<script>
+  connection_reuse_test("resources/fake_responses.py",
+    {
+      'on_200': invariants.assert_tao_pass_no_redirect_https,
+      'on_304': invariants.assert_tao_pass_304_not_modified_https,
+    }, "Reuse an HTTPS connection");
+</script>
+</head>
+<body>
+<h1>Description</h1>
+<p>See <a href="resources/connection-reuse-test.js">the included test
+  script</a></p>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/cors-preflight.any.js b/test/fixtures/wpt/resource-timing/cors-preflight.any.js
new file mode 100644
index 00000000000000..4b980e7d0af89e
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/cors-preflight.any.js
@@ -0,0 +1,49 @@
+// META: script=/common/utils.js
+// META: script=/common/get-host-info.sub.js
+
+// Because apache decrements the Keep-Alive max value on each request, the
+// transferSize will vary slightly between requests for the same resource.
+const fuzzFactor = 3;  // bytes
+
+const {HTTP_REMOTE_ORIGIN} = get_host_info();
+const url = new URL('/resource-timing/resources/preflight.py',
+    HTTP_REMOTE_ORIGIN).href;
+
+// The header bytes are expected to be > |minHeaderSize| and
+// < |maxHeaderSize|. If they are outside this range the test will fail.
+const minHeaderSize = 100;
+const maxHeaderSize = 1024;
+
+promise_test(async () => {
+  const checkCorsAllowed = response => response.arrayBuffer();
+  const requirePreflight = {headers: {'X-Require-Preflight' : '1'}};
+  const collectEntries = new Promise(resolve => {
+    let entriesSeen = [];
+    new PerformanceObserver(entryList => {
+      entriesSeen = entriesSeen.concat(entryList.getEntries());
+      if (entriesSeen.length > 2) {
+        throw new Error(`Saw too many PerformanceResourceTiming entries ` +
+            `(${entriesSeen.length})`);
+      }
+      if (entriesSeen.length == 2) {
+        resolve(entriesSeen);
+      }
+    }).observe({"type": "resource"});
+  });
+
+  // Although this fetch doesn't send a pre-flight request, the server response
+  // will allow cross-origin requests explicitly with the
+  // Access-Control-Allow-Origin header.
+  await fetch(url).then(checkCorsAllowed);
+
+  // This fetch will send a pre-flight request to do the CORS handshake
+  // explicitly.
+  await fetch(url, requirePreflight).then(checkCorsAllowed);
+
+  const entries = await collectEntries;
+  assert_greater_than(entries[0].transferSize, 0, 'No-preflight transferSize');
+  const lowerBound = entries[0].transferSize - fuzzFactor;
+  const upperBound = entries[0].transferSize + fuzzFactor;
+  assert_between_exclusive(entries[1].transferSize, lowerBound, upperBound,
+      'Preflighted transferSize');
+}, 'PerformanceResourceTiming sizes fetch with preflight test');
diff --git a/test/fixtures/wpt/resource-timing/cross-origin-iframe.html b/test/fixtures/wpt/resource-timing/cross-origin-iframe.html
new file mode 100644
index 00000000000000..69daebffaf2a24
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/cross-origin-iframe.html
@@ -0,0 +1,33 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Test ResourceTiming reporting for cross-origin iframe.</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<script src="resources/entry-invariants.js"></script>
+<script src="resources/observe-entry.js"></script>
+</head>
+<body>
+<body>
+<script>
+  const {REMOTE_ORIGIN} = get_host_info();
+
+  promise_test(async t => {
+    const iframe = document.createElement('iframe');
+    t.add_cleanup(() => iframe.remove());
+    iframe.src = `${REMOTE_ORIGIN}/resource-timing/resources/green.html`;
+    document.body.appendChild(iframe);
+    const entry = await observe_entry(iframe.src);
+    invariants.assert_tao_failure_resource(entry);
+  }, "A cross-origin iframe should report an opaque RT entry");
+
+  promise_test(async t => {
+    const iframe = document.createElement('iframe');
+    t.add_cleanup(() => iframe.remove());
+    iframe.src = `${REMOTE_ORIGIN}/resource-timing/resources/TAOResponse.py?tao=wildcard`;
+    document.body.appendChild(iframe);
+    const entry = await observe_entry(iframe.src);
+    invariants.assert_tao_pass_no_redirect_http(entry);
+  }, "A cross-origin iframe with TAO enabled should report a full RT entry");
+
+  </script>
diff --git a/test/fixtures/wpt/resource-timing/cross-origin-redirects.html b/test/fixtures/wpt/resource-timing/cross-origin-redirects.html
new file mode 100644
index 00000000000000..0bdc0547e577f6
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/cross-origin-redirects.html
@@ -0,0 +1,102 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>This test validates the values in resource timing for cross-origin
+redirects.</title>
+<link rel="author" title="Intel" href="http://www.intel.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#sec-performanceresourcetiming"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/custom-cors-response.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<script src="resources/entry-invariants.js"></script>
+<script src="resources/resource-loaders.js"></script>
+<script src="resources/tao-response.js"></script>
+</head>
+<body>
+<script>
+const {ORIGIN, REMOTE_ORIGIN} = get_host_info();
+
+const HTTP_SO_to_XO_redirect_url = url => {
+  // Make an initial request to a same-domain resource that will return a 302
+  // redirect to the given (possibly cross-origin) url.
+  return `/resource-timing/resources/redirect-cors.py?location=${url}`;
+};
+
+const HTTP_SO_resource = () => {
+  if (location.protocol != "http:") {
+    throw new Error("Can only make an HTTP SO request if this page was " +
+      "served over HTTP.");
+  }
+  return tao_response("*", ORIGIN);
+};
+
+const HTTP_XO_redirect = (url, tao) => {
+  const ret = new URL(
+    `${REMOTE_ORIGIN}/resource-timing/resources/redirect-cors.py`);
+  ret.searchParams.append("location", url);
+  ret.searchParams.append("allow_origin", "*");
+  ret.searchParams.append("timing_allow_origin", tao);
+  return ret.href;
+};
+
+attribute_test(
+  load.iframe, HTTP_SO_to_XO_redirect_url(custom_cors_response({},
+    REMOTE_ORIGIN)),
+  invariants.assert_http_to_cross_origin_redirected_resource,
+  "Verify that cross-origin resources' timings aren't exposed through HTTP " +
+  "redirects.");
+
+attribute_test(
+  load.iframe, HTTP_SO_to_XO_redirect_url(remote_tao_response("no-match")),
+  invariants.assert_cross_origin_redirected_resource,
+  "Verify that a redirected cross-origin resources' timings aren't exposed " +
+  "when the TAO check fails.");
+
+attribute_test(
+  load.iframe, HTTP_SO_to_XO_redirect_url(remote_tao_response("*")),
+  invariants.assert_http_to_tao_enabled_cross_origin_https_redirected_resource,
+  "Verify that cross-origin resources' timings are exposed when the TAO " +
+  "check succeeds. Also verify that secureConnectionStart is 0 since the " +
+  "original request was over HTTP.");
+
+attribute_test(
+  load.iframe, HTTP_XO_redirect(HTTP_XO_redirect(HTTP_SO_resource(), "*"), "*"),
+  invariants.assert_http_to_tao_enabled_cross_origin_https_redirected_resource,
+  "Verify that a redirect chain through cross-origin resources have their " +
+  "timings exposed when all TAO checks succeed. Also verify that " +
+  "secureConnectionStart is 0 since the original request was over HTTP.");
+
+const failure_permutations = [
+  ["fail", "fail", "fail"],
+  ["fail", "fail", "*"   ],
+  ["fail", "*",    "fail"],
+  ["fail", "*",    "*"   ],
+  ["*",    "fail", "fail"],
+  ["*",    "fail", "*"   ],
+  ["*",    "*",    "fail"],
+];
+const test_case = (so_tao, xo1_tao, xo2_tao) => {
+  return HTTP_XO_redirect(HTTP_XO_redirect(HTTP_SO_resource(
+    so_tao), xo2_tao), xo1_tao);
+};
+const test_label = perm => {
+  return perm.map(x => {
+    if (x == "*" ) return "PASS";
+    if (x == "fail" ) return "FAIL";
+    throw new Error(`unexpected element ${x}`);
+  }).join(" -> ");
+};
+for (const permutation of failure_permutations) {
+  attribute_test(
+    load.iframe, test_case.apply(permutation),
+    invariants.assert_tao_failure_resource,
+    `Verify that a redirect chain through cross-origin resources do not have ` +
+    `their timings exposed when any of the TAO checks fail. ` +
+    `(${test_label(permutation)})`);
+}
+
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/cross-origin-start-end-time-with-redirects.html b/test/fixtures/wpt/resource-timing/cross-origin-start-end-time-with-redirects.html
new file mode 100644
index 00000000000000..1b107d3aef7764
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/cross-origin-start-end-time-with-redirects.html
@@ -0,0 +1,32 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>This test validates the values in resource timing for cross-origin
+redirects.</title>
+<link rel="author" title="Noam Rosenthal" href="noam@webkit.org">
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#sec-performanceresourcetiming"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<script src="resources/resource-loaders.js"></script>
+<script src="resources/entry-invariants.js"></script>
+</head>
+<body>
+<script>
+const {REMOTE_ORIGIN} = get_host_info();
+const delay = 2
+const blank_page = `/resource-timing/resources/blank_page_green.htm`;
+const destUrl = `/common/slow-redirect.py?delay=${delay}&location=${REMOTE_ORIGIN}/${blank_page}`;
+
+const timeBefore = performance.now()
+attribute_test(load.iframe, destUrl, entry => {
+    assert_equals(entry.startTime, entry.fetchStart, 'startTime and fetchStart should be equal');
+    assert_greater_than(entry.startTime, timeBefore, 'startTime and fetchStart should be greater than the time before fetching');
+    // See https://github.com/w3c/resource-timing/issues/264
+    assert_less_than(Math.round(entry.startTime - timeBefore), delay * 1000, 'startTime should not expose redirect delays');
+}, "Verify that cross-origin resources don't implicitly expose their redirect timings")
+
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/cross-origin-status-codes.html b/test/fixtures/wpt/resource-timing/cross-origin-status-codes.html
new file mode 100644
index 00000000000000..197a7663396ef6
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/cross-origin-status-codes.html
@@ -0,0 +1,70 @@
+<!doctype html>
+<html>
+<head>
+<title>Resource Timing: PerformanceResourceTiming attributes shouldn't change
+  if the HTTP status code changes</title>
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#sec-performanceresourcetiming"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src=/common/get-host-info.sub.js></script>
+</head>
+<body>
+<img id="img_200">
+<img id="img_307">
+<img id="img_404">
+<img id="img_502">
+<script id="script_200"></script>
+<script id="script_307"></script>
+<script id="script_404"></script>
+<script id="script_502"></script>
+<script>
+
+const listenForPerformanceEntries = num_expected => {
+  return new Promise(resolve => {
+    let results = [];
+    new PerformanceObserver(entryList => {
+      entryList.getEntries().forEach(entry => {
+        if (!entry.name.includes("status-code"))
+          return;
+
+        results.push(entry);
+        if (results.length == num_expected) {
+          resolve(results);
+        }
+      });
+    }).observe({entryTypes: ['resource']});
+  });
+}
+
+promise_test(async t => {
+  const destUrl = get_host_info().HTTP_REMOTE_ORIGIN + '/resource-timing/resources/';
+  const statusCodes = ['200', '307', '404', '502'];
+
+  let expected_entry_count = 0;
+  statusCodes.forEach(status => {
+    document.getElementById(`img_${status}`).src = `${destUrl}status-code.py?status=${status}`;
+    document.getElementById(`script_${status}`).src = `${destUrl}status-code.py?status=${status}&script=1`;
+    expected_entry_count += 2;
+  });
+
+  const entries = await listenForPerformanceEntries(expected_entry_count);
+
+  // We will check that the non-timestamp values of the entry match for all
+  // entries.
+  const keys = [
+    'entryType',
+    'nextHopProtocol',
+    'transferSize',
+    'encodedBodySize',
+    'decodedBodySize',
+  ];
+
+  const first = entries[0];
+  entries.slice(1).forEach(entry => {
+    keys.forEach(attribute => {
+      assert_equals(entry[attribute], first[attribute],
+        `There must be no discernible difference for the ${attribute} ` +
+        `attribute but found a difference for the ${entry.name} resource.`);
+  })});
+}, "Make sure cross origin resource fetch failures with different status codes are indistinguishable");
+</script>
diff --git a/test/fixtures/wpt/resource-timing/document-domain-no-impact-opener.html b/test/fixtures/wpt/resource-timing/document-domain-no-impact-opener.html
new file mode 100644
index 00000000000000..69df2f27fa5b19
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/document-domain-no-impact-opener.html
@@ -0,0 +1,16 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+<meta charset="utf-8">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<script>
+// Open a document on one of hosts on the web-platform test domain, so that
+// document.domain will set a valid domain, turning the frame into a
+// cross-origin frame.
+const {OTHER_ORIGIN} = get_host_info();
+const openee = window.open(OTHER_ORIGIN +
+               "/resource-timing/resources/document-domain-no-impact.html");
+fetch_tests_from_window(openee);
+</script>
diff --git a/test/fixtures/wpt/resource-timing/entries-for-network-errors.sub.https.html b/test/fixtures/wpt/resource-timing/entries-for-network-errors.sub.https.html
new file mode 100644
index 00000000000000..95849d282621ff
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/entries-for-network-errors.sub.https.html
@@ -0,0 +1,35 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>This test validates that a failed cross-origin fetch creates an opaque network timing entry.
+</title>
+<link rel="author" title="Noam Rosenthal" href="noam@webkit.org">
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#sec-performanceresourcetiming"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<script src="resources/entry-invariants.js"></script>
+</head>
+<body>
+<script>
+const validDataURL = 'data:,Hello%2C%20World%21'
+const {REMOTE_ORIGIN, ORIGINAL_HOST, HTTP_PORT} = get_host_info();
+const validXmlUrl = '/common/dummy.xml';
+
+network_error_entry_test(
+    `${REMOTE_ORIGIN}${validXmlUrl}`, null, `failed cross-origin requests`);
+
+network_error_entry_test(`/common/redirect.py?location=${validDataURL}`, null, "non-HTTP redirect");
+network_error_entry_test('//{{hosts[][nonexistent]}}/common/dummy.xml', null, "DNS failure");
+network_error_entry_test(`http://${ORIGINAL_HOST}:${HTTP_PORT}/commo/dummy.xml`, null, "Mixed content");
+
+network_error_entry_test('/common/dummy.xml', {cache: 'only-if-cached', mode: 'same-origin'},
+    "only-if-cached resource that was not cached");
+
+network_error_entry_test(
+    `/element-timing/resources/multiple-redirects.py?redirect_count=22&final_resource=${validXmlUrl}`,
+    null, "too many redirects");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/entry-attributes.html b/test/fixtures/wpt/resource-timing/entry-attributes.html
new file mode 100644
index 00000000000000..94f219f229107e
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/entry-attributes.html
@@ -0,0 +1,39 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing: PerformanceResourceTiming attributes</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help"
+  href="https://www.w3.org/TR/resource-timing-2/#timing-allow-origin"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/resource-loaders.js"></script>
+<script src="resources/entry-invariants.js"></script>
+<script>
+attribute_test(
+  load.image, "resources/fake_responses.py#hash=1",
+  entry => {
+    assert_true(entry.name.includes('#hash=1'),
+      "There should be a hash in the resource name");
+    invariants.assert_tao_pass_no_redirect_http(entry);
+  },
+  "Image resources should generate conformant entries");
+
+attribute_test(
+  load.font, "/fonts/Ahem.ttf",
+  invariants.assert_tao_pass_no_redirect_http,
+  "Font resources should generate conformant entries");
+
+attribute_test(
+  load.image, "/common/redirect.py?location=resources/fake_responses.py",
+  invariants.assert_same_origin_redirected_resource,
+  "Same-origin redirects should populate redirectStart/redirectEnd");
+</script>
+</head>
+<body>
+<h1>Description</h1>
+<p>This test validates that PerformanceResourceTiming entries' attributes are
+populated with the correct values.</p>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/event-source-timing.html b/test/fixtures/wpt/resource-timing/event-source-timing.html
new file mode 100644
index 00000000000000..917e7c34952cd6
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/event-source-timing.html
@@ -0,0 +1,32 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<meta name="timeout" content="long">
+<title>Resource Timing: EventSource timing behavior</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resource-timing/resources/observe-entry.js"></script>
+</head>
+</script>
+<script>
+    async_test(t => {
+        const repetitions = 2;
+        const url = new URL(`/eventsource/resources/message.py`, location.href);
+        const eventSource = new EventSource(url);
+        let messages = 0;
+        t.add_cleanup(() => eventSource.close());
+        eventSource.addEventListener('message', () => {
+            ++messages;
+        })
+
+        new PerformanceObserver(() => {
+            const entries = performance.getEntriesByName(url);
+            assert_greater_than_equal(entries.length, messages - 1);
+            if (entries.length === repetitions)
+                t.done();
+        }).observe({type: 'resource'});
+    }, "ResourceTiming for EventSource should reflect number of re-connections to source");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/fetch-cross-origin-redirect.https.html b/test/fixtures/wpt/resource-timing/fetch-cross-origin-redirect.https.html
new file mode 100644
index 00000000000000..4193422653a595
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/fetch-cross-origin-redirect.https.html
@@ -0,0 +1,33 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Test cross-origin fetch redirects have the right values.</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#sec-performanceresourcetiming"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<script src="resources/entry-invariants.js"></script>
+<script src="resources/resource-loaders.js"></script>
+<script>
+
+const {REMOTE_ORIGIN, ORIGIN} = get_host_info();
+const redirect = "/common/redirect.py?" +
+                 "location=/resource-timing/resources/green.html";
+const cross_origin_redirect = REMOTE_ORIGIN + redirect;
+const same_origin_redirect = ORIGIN + redirect;
+
+attribute_test(
+  url => fetch(url, {mode: "no-cors", credentials: "include"}),
+  new URL(cross_origin_redirect).href,
+  invariants.assert_cross_origin_redirected_resource,
+  "Test fetching through a cross-origin redirect URL"
+);
+
+attribute_test(
+  url => fetch(url, {mode: "no-cors", credentials: "include"}),
+  new URL(same_origin_redirect).href,
+  invariants.assert_same_origin_redirected_resource,
+  "Test fetching through a same-origin redirect URL"
+);
+
+</script>
diff --git a/test/fixtures/wpt/resource-timing/font-timestamps.html b/test/fixtures/wpt/resource-timing/font-timestamps.html
new file mode 100644
index 00000000000000..56ecb5c4bfddb6
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/font-timestamps.html
@@ -0,0 +1,62 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Test cross-origin fetch redirects have the right values.</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<body>
+<script>
+const load_font = url => {
+  document.body.innerHTML = `
+    <style>
+    @font-face {
+        font-family: ahem;
+        src: url('${url}');
+    }
+    </style>
+    <div style="font-family: ahem;">This fetches ahem font.</div>
+  `;
+  return document.fonts.ready;
+};
+
+const run_test = async (t, url) => {
+  // Set up PerformanceObserver
+  const href = new URL(url).href;
+  const setPerformanceObserver = new Promise(resolve => {
+    const po = new PerformanceObserver(resolve);
+    po.observe({type: "resource"});
+  });
+
+  // Load the font resource and wait for it to be fetched.
+  await load_font(href);
+
+  // Wait for an entry
+  const timeout = new Promise(resolve => t.step_timeout(resolve, 3000));
+  const list = await Promise.race([setPerformanceObserver, timeout]);
+  assert_equals(typeof(list), "object", "No iframe entry was fired");
+  const entries = list.getEntriesByName(url);
+  assert_equals(entries.length, 1);
+
+  // Test entry values
+  const entry = entries[0];
+  assert_greater_than(entry.fetchStart, 0, "fetchStart should be greater than 0 in redirects.");
+  assert_greater_than_equal(entry.domainLookupStart, entry.fetchStart, "domainLookupStart should be more than 0 in same-origin redirect.");
+  assert_greater_than_equal(entry.domainLookupEnd, entry.domainLookupStart, "domainLookupEnd should be more than 0 in same-origin redirect.");
+  assert_greater_than_equal(entry.connectStart, entry.domainLookupEnd, "connectStart should be more than 0 in same-origin redirect.");
+  assert_greater_than_equal(entry.secureConnectionStart, entry.connectStart, "secureConnectionStart should be more than 0 in same-origin redirect.");
+  assert_greater_than_equal(entry.connectEnd, entry.secureConnectionStart, "connectEnd should be more than 0 in same-origin redirect.");
+  assert_greater_than_equal(entry.requestStart, entry.connectEnd, "requestStart should be more than 0 in same-origin redirect.");
+  assert_greater_than_equal(entry.responseStart, entry.requestStart, "responseStart should be more than 0 in same-origin redirect.");
+  assert_greater_than_equal(entry.responseEnd, entry.responseStart, "responseEnd should be greater than 0 in redirects.");
+  assert_greater_than_equal(entry.duration, 0, "duration should be greater than 0 in redirects.");
+}
+
+const {HTTPS_REMOTE_ORIGIN} = get_host_info();
+promise_test(t => {
+  return run_test(t, HTTPS_REMOTE_ORIGIN + "/fonts/Ahem.ttf");
+}, "Test a font's timestamps");
+
+promise_test(t => {
+  return run_test(t, HTTPS_REMOTE_ORIGIN + "/resource-timing/resources/cors-ahem.py?pipe=trickle(d1)");
+}, "Test a font's timestamps with delays");
+</script>
diff --git a/test/fixtures/wpt/resource-timing/frameset-timing.html b/test/fixtures/wpt/resource-timing/frameset-timing.html
new file mode 100644
index 00000000000000..1a6facbfc4d623
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/frameset-timing.html
@@ -0,0 +1,6 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Test the sequence of events when reporting timing for frames.</title>
+<frameset>
+  <frame src="resources/frameset-timing-frame.html" />
+</frameset>
diff --git a/test/fixtures/wpt/resource-timing/idlharness.any.js b/test/fixtures/wpt/resource-timing/idlharness.any.js
new file mode 100644
index 00000000000000..aa860d3dd16a71
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/idlharness.any.js
@@ -0,0 +1,24 @@
+// META: script=/resources/WebIDLParser.js
+// META: script=/resources/idlharness.js
+// META: timeout=long
+
+'use strict';
+
+// https://w3c.github.io/resource-timing/
+
+idl_test(
+  ['resource-timing'],
+  ['performance-timeline', 'hr-time', 'dom', 'html'],
+  idl_array => {
+    try {
+      self.resource = performance.getEntriesByType('resource')[0];
+    } catch (e) {
+      // Will be surfaced when resource is undefined below.
+    }
+
+    idl_array.add_objects({
+      Performance: ['performance'],
+      PerformanceResourceTiming: ['resource']
+    });
+  }
+);
diff --git a/test/fixtures/wpt/resource-timing/iframe-failed-commit.html b/test/fixtures/wpt/resource-timing/iframe-failed-commit.html
new file mode 100644
index 00000000000000..1da207d2fbe05e
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/iframe-failed-commit.html
@@ -0,0 +1,108 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing - test that unsuccessful iframes create entries</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href=
+  "https://www.w3.org/TR/resource-timing-2/#resources-included-in-the-performanceresourcetiming-interface"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<script src="resources/entry-invariants.js"></script>
+<script src="resources/resource-loaders.js"></script>
+<body>
+<script>
+
+// Like load.iframe but fetches the iframe under a "default-src 'none'"
+// Content-Security-Policy.
+const load_iframe_with_csp = async path => {
+  return load.iframe_with_attrs(path, {"csp": "default-src 'none'"});
+};
+
+// Runs a test (labeled by the given label) to verify that loading an iframe
+// with the given URL generates a PerformanceResourceTiming entry and that the
+// entry does not expose sensitive timing attributes.
+const masked_entry_test = (url, label) => {
+  return attribute_test(load.iframe, url,
+    invariants.assert_tao_failure_resource, label);
+};
+
+// Runs a test (labeled by the given label) to verify that loading an iframe
+// with the given URL generates a PerformanceResourceTiming entry and that the
+// entry does expose sensitive timing attributes.
+const unmasked_entry_with_csp_test = (url, label) => {
+  return attribute_test(load_iframe_with_csp, url,
+    invariants.assert_tao_pass_no_redirect_http, label);
+};
+
+// Runs a test (labeled by the given label) to verify that loading an iframe
+// with the given URL under a "default-src 'none' Content-Security-Policy
+// generates a PerformanceResourceTiming entry and that the entry does not
+// expose sensitive timing attributes.
+const masked_entry_with_csp_test = (url, label) => {
+  return attribute_test(load_iframe_with_csp, url,
+    invariants.assert_tao_failure_resource, label);
+};
+
+// Runs a test (labeled by the given label) to verify that loading an iframe
+// with the given URL, an empty response body and under a "default-src 'none'
+// Content-Security-Policy generates a PerformanceResourceTiming entry and that
+// the entry does expose sensitive timing attributes.
+const empty_unmasked_entry_with_csp_test = (url, label) => {
+  return attribute_test(load_iframe_with_csp, url,
+    invariants.assert_tao_pass_no_redirect_http_empty, label);
+};
+
+const {REMOTE_ORIGIN, ORIGINAL_HOST, HTTPS_PORT} = get_host_info();
+const unhosted_url = `https://nonexistent.${ORIGINAL_HOST}:${HTTPS_PORT}/`;
+
+masked_entry_test(
+  unhosted_url,
+  "Test iframe from non-existent host gets reported");
+
+masked_entry_test(
+  "/resource-timing/resources/fake_responses.py?redirect=" + unhosted_url,
+  "Test iframe redirecting to non-existent host gets reported");
+
+unmasked_entry_with_csp_test("/resource-timing/resources/csp-default-none.html",
+  "Same-origin iframe that complies with CSP attribute gets reported");
+
+unmasked_entry_with_csp_test("/resource-timing/resources/green-frame.html",
+  "Same-origin iframe that doesn't comply with CSP attribute gets reported");
+
+masked_entry_with_csp_test(
+  new URL("/resource-timing/resources/csp-default-none.html", REMOTE_ORIGIN),
+  "Cross-origin iframe that complies with CSP attribute gets reported");
+
+masked_entry_with_csp_test(
+  new URL("/resource-timing/resources/green-frame.html", REMOTE_ORIGIN),
+  "Cross-origin iframe that doesn't comply with CSP attribute gets reported");
+
+empty_unmasked_entry_with_csp_test(
+  "/resource-timing/resources/200_empty.asis",
+  "Same-origin empty iframe with a 200 status gets reported");
+
+masked_entry_with_csp_test(
+  new URL("/resource-timing/resources/200_empty.asis", REMOTE_ORIGIN),
+  "Cross-origin empty iframe with a 200 status gets reported");
+
+unmasked_entry_with_csp_test(
+    new URL("/resource-timing/resources/204_empty.asis"),
+    "Same-origin empty iframe with a 204 status gets reported");
+
+unmasked_entry_with_csp_test(
+    new URL("/resource-timing/resources/205_empty.asis"),
+    "Same-origin empty iframe with a 205 status gets reported");
+
+masked_entry_with_csp_test(
+    new URL("/resource-timing/resources/204_empty.asis", REMOTE_ORIGIN),
+    "Cross-origin empty iframe with a 204 status gets reported");
+
+masked_entry_with_csp_test(
+    new URL("/resource-timing/resources/205_empty.asis", REMOTE_ORIGIN),
+    "Cross-origin empty iframe with a 205 status gets reported");
+
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/iframe-non-html.html b/test/fixtures/wpt/resource-timing/iframe-non-html.html
new file mode 100644
index 00000000000000..a5df3b034899d1
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/iframe-non-html.html
@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Test the sequence of events when reporting iframe timing.</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/resource-loaders.js"></script>
+<body>
+<script>
+    function test(href, type) {
+        promise_test(async t => {
+            await load.iframe(href);
+            const entries = performance.getEntriesByType('resource').filter(({name}) => name.includes(href));
+            assert_equals(entries.length, 1);
+            assert_equals(entries[0].initiatorType, 'iframe');
+        }, `Iframes should report resource timing for ${type} iframes`);
+    }
+
+    test('/common/square.png', 'image');
+    test('/common/dummy.xhtml', 'xhtml');
+    test('/common/dummy.xml', 'xml');
+    test('/common/text-plain.txt', 'text');
+</script>
+</body>
\ No newline at end of file
diff --git a/test/fixtures/wpt/resource-timing/iframe-redirect-without-location.html b/test/fixtures/wpt/resource-timing/iframe-redirect-without-location.html
new file mode 100644
index 00000000000000..bae5f3112fe291
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/iframe-redirect-without-location.html
@@ -0,0 +1,17 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Test the sequence of events when reporting iframe timing.</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/resource-loaders.js"></script>
+<body>
+<script>
+    promise_test(async t => {
+        const href = new URL('resources/redirect-without-location.py', location.href);
+        await load.iframe(href);
+        const entries = performance.getEntriesByType('resource').filter(({name}) => name.startsWith(href));
+        assert_equals(entries.length, 1);
+        assert_equals(entries[0].initiatorType, 'iframe');
+    }, 'Iframes should report resource timing for redirect responses without a location');
+</script>
+</body>
\ No newline at end of file
diff --git a/test/fixtures/wpt/resource-timing/iframe-sequence-of-events.html b/test/fixtures/wpt/resource-timing/iframe-sequence-of-events.html
new file mode 100644
index 00000000000000..5f99a5cab2de6b
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/iframe-sequence-of-events.html
@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Test the sequence of events when reporting iframe timing.</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/frame-timing.js"></script>
+<body>
+<script>
+  test_frame_timing_before_load_event('iframe');
+  test_frame_timing_change_src('iframe');
+</script>
+</body>
\ No newline at end of file
diff --git a/test/fixtures/wpt/resource-timing/iframe-with-download.html b/test/fixtures/wpt/resource-timing/iframe-with-download.html
new file mode 100644
index 00000000000000..9583024dd8faa9
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/iframe-with-download.html
@@ -0,0 +1,24 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Test the sequence of events when reporting iframe timing.</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/resource-loaders.js"></script>
+<body>
+<script>
+    promise_test(async t => {
+        const href = new URL('resources/download.asis', location.href);
+        const iframe = document.createElement('iframe');
+        iframe.src = href;
+        const errored = new Promise(resolve => iframe.addEventListener('error', resolve));
+        const loaded = new Promise(resolve => iframe.addEventListener('load', resolve));
+        document.body.appendChild(iframe);
+        const timeout = 2000;
+        t.add_cleanup(() => iframe.remove());
+        const expired = new Promise(resolve => t.step_timeout(resolve, timeout));
+        await Promise.any([loaded, expired, errored]);
+        const entries = performance.getEntriesByType('resource').filter(({name}) => name.startsWith(href));
+        assert_equals(entries.length, 0);
+    }, 'Iframes should not report resource timing for non-handled mime-types (downloads)');
+</script>
+</body>
\ No newline at end of file
diff --git a/test/fixtures/wpt/resource-timing/image-sequence-of-events.html b/test/fixtures/wpt/resource-timing/image-sequence-of-events.html
new file mode 100644
index 00000000000000..630fed78c964bd
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/image-sequence-of-events.html
@@ -0,0 +1,29 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Test the sequence of events when reporting image timing.</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<body>
+<script>
+  function test_image_sequence(src, event, t) {
+    const image = document.createElement('img');
+    const absoluteURL = new URL(src, location.href).toString();
+    document.body.appendChild(image);
+    t.add_cleanup(() => image.remove());
+    return new Promise(resolve => {
+      image.addEventListener(event, t.step_func(() => {
+        assert_equals(performance.getEntriesByName(absoluteURL).length, 1);
+        resolve();
+      }));
+      image.src = src;
+    });
+  }
+  promise_test(t => test_image_sequence('resources/blue.png', 'load', t),
+  "An image should receive its load event after the ResourceTiming entry is available");
+
+  promise_test(t => test_image_sequence('resources/nothing-at-all.png', 'error', t),
+  "A non-existent (404) image should receive its error event after the ResourceTiming entry is available");
+
+  promise_test(t => test_image_sequence('resources/invalid.png', 'error', t),
+  "An invalid image should receive its error event after the ResourceTiming entry is available");
+</script>
diff --git a/test/fixtures/wpt/resource-timing/initiator-type-for-script.html b/test/fixtures/wpt/resource-timing/initiator-type-for-script.html
new file mode 100644
index 00000000000000..72173398d56aa4
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/initiator-type-for-script.html
@@ -0,0 +1,67 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>This test validates that the initiatorType information for various
+Resource Timing entries is accurate for scripts.</title>
+<link rel="help"
+      href="https://www.w3.org/TR/resource-timing-2/#dom-performanceresourcetiming-initiatortype"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<script src="resources/resource-loaders.js"></script>
+<script src="resources/entry-invariants.js"></script>
+<!-- Tested resources -->
+<script src="resources/empty_script.js?id=blocking"></script>
+<script src="resources/empty_script.js?id=async" async></script>
+<script src="resources/empty_script.js?id=async_false" async=false></script>
+<script src="resources/empty_script.js?id=defer" defer></script>
+<script>
+document.write("<script src='resources/empty_script.js?id=doc_written'></scr"
+               + "ipt>");
+
+const head = document.getElementsByTagName("head")[0];
+const s1 = document.createElement("script");
+s1.src = "empty_script.js?id=appended";
+head.appendChild(s1);
+
+const s2 = document.createElement("script");
+s2.src = "empty_script.js?id=appended_async";
+s2.async = true;
+head.appendChild(s2);
+
+const s3 = document.createElement("script");
+s3.src = "empty_script.js?id=appended_aync_false";
+s3.async = false;
+head.appendChild(s3);
+
+const s4 = document.createElement("script");
+s4.src = "empty_script.js?id=appended_defer";
+s4.defer = true;
+head.appendChild(s4);
+</script>
+</head>
+<body>
+<script>
+
+const wait_for_onload = () => {
+  return new Promise(resolve => {
+    window.addEventListener("load", resolve);
+})};
+
+promise_test(
+  async () => {
+    await wait_for_onload();
+
+    const entry_list = performance.getEntriesByType("resource");
+    for (entry of entry_list) {
+      if (entry.name.includes("empty_script.js")) {
+        assert_equals(entry.initiatorType, "script",
+                      "initiatorType should be 'script' for " + entry.name);
+      }
+    }
+}, "Validate initiatorType for scripts is 'script'");
+</script>
+</body>
+</html>
+
diff --git a/test/fixtures/wpt/resource-timing/initiator-type/audio.html b/test/fixtures/wpt/resource-timing/initiator-type/audio.html
new file mode 100644
index 00000000000000..f09fc618478fd6
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/initiator-type/audio.html
@@ -0,0 +1,34 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing initiator type: audio</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#dom-performanceresourcetiming-initiatortype"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resource-timing/resources/observe-entry.js"></script>
+<script src="resources/initiator-type-test.js"></script>
+</head>
+<body>
+<audio src="/resource-timing/resources/empty.py?id=src"></audio>
+<audio>
+  <source src="/resource-timing/resources/empty.py?id=source-wav"
+    type="audio/wav" />
+</audio>
+<audio>
+  <source src="/resource-timing/resources/empty.py?id=source-mpeg"
+    type="audio/mpeg" />
+</audio>
+<audio>
+  <source src="/resource-timing/resources/empty.py?id=source-ogg"
+    type="audio/ogg" />
+</audio>
+<script>
+  initiator_type_test("empty.py?id=src", "audio", "<audio src> without 'type' attribute");
+  initiator_type_test("empty.py?id=source-wav", "audio", "<source src> with type 'audio/wav'");
+  initiator_type_test("empty.py?id=source-mpeg", "audio", "<source src> with type 'audio/mpeg'");
+  initiator_type_test("empty.py?id=source-ogg", "audio", "<source src> with type 'audio/ogg'");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/initiator-type/dynamic-insertion.html b/test/fixtures/wpt/resource-timing/initiator-type/dynamic-insertion.html
new file mode 100644
index 00000000000000..8ce05b3cfeddd6
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/initiator-type/dynamic-insertion.html
@@ -0,0 +1,41 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing - initiatorType with dynamic insertion</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#dom-performanceresourcetiming-initiatortype"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resource-timing/resources/entry-invariants.js"></script>
+<script src="/resource-timing/resources/resource-loaders.js"></script>
+<script>
+  const dynamic_initiator_type_test = (loader, path, expected_type,
+      resource_type) => {
+    attribute_test(loader, path, entry => {
+      assert_equals(entry.initiatorType, expected_type);
+    }, `A ${resource_type} should have the '${expected_type}' initiator type.`);
+  };
+
+  dynamic_initiator_type_test(load.image, "resources/resource_timing_test0.png",
+    "img", "image");
+  // Note that, to download a font, 'load.font' uses a <style> element to
+  // construct a font-face that is then applied to a <div>. Since it's a <style>
+  // element requesting the resource, the initiator type is 'css', not 'font'.
+  dynamic_initiator_type_test(load.font, "/fonts/Ahem.ttf", "css", "font");
+  dynamic_initiator_type_test(load.stylesheet,
+    "resources/resource_timing_test0.css", "link", "stylesheet");
+  dynamic_initiator_type_test(load.iframe, "resources/green.html", "iframe",
+    "iframe");
+  dynamic_initiator_type_test(load.script, "resources/empty.js", "script",
+    "script");
+  dynamic_initiator_type_test(load.xhr_sync, "resources/empty.py",
+    "xmlhttprequest", "XMLHttpRequest");
+</script>
+</head>
+<body>
+<h1>Description</h1>
+<p>This test validates that the initiatorType field is correct even when an
+element is dynamically inserted.</p>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/initiator-type/embed.html b/test/fixtures/wpt/resource-timing/initiator-type/embed.html
new file mode 100644
index 00000000000000..c7a505afac90c3
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/initiator-type/embed.html
@@ -0,0 +1,20 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing initiator type: embed</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#dom-performanceresourcetiming-initiatortype"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resource-timing/resources/observe-entry.js"></script>
+<script src="resources/initiator-type-test.js"></script>
+</head>
+<body>
+<embed src="/resource-timing/resources/resource_timing_test0.css"
+    type="text/css">
+<script>
+  initiator_type_test("resource_timing_test0.css", "embed", "<embed>");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/initiator-type/frameset.html b/test/fixtures/wpt/resource-timing/initiator-type/frameset.html
new file mode 100644
index 00000000000000..697549a14dd97a
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/initiator-type/frameset.html
@@ -0,0 +1,22 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing initiator type: frameset</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#dom-performanceresourcetiming-initiatortype"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resource-timing/resources/observe-entry.js"></script>
+<script src="resources/initiator-type-test.js"></script>
+<script>
+  initiator_type_test("green.html", "frame", "<frame> in a <frameset>");
+</script>
+</head>
+<!-- Although framesets were deprecated in HTML5, we still want to make sure
+  Resource Timing is emitting entries for the underlying resources' requests.
+-->
+<frameset>
+  <frame src="/resource-timing/resources/green.html">
+</frameset>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/initiator-type/iframe.html b/test/fixtures/wpt/resource-timing/initiator-type/iframe.html
new file mode 100644
index 00000000000000..0becd86894be23
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/initiator-type/iframe.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing initiator type: iframe</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#dom-performanceresourcetiming-initiatortype"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resource-timing/resources/observe-entry.js"></script>
+<script src="resources/initiator-type-test.js"></script>
+</head>
+<body>
+<iframe src="/resource-timing/resources/green.html"></iframe>
+<script>
+  initiator_type_test("green.html", "iframe", "<iframe>");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/initiator-type/img-srcset.html b/test/fixtures/wpt/resource-timing/initiator-type/img-srcset.html
new file mode 100644
index 00000000000000..b8c81fbb251d5a
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/initiator-type/img-srcset.html
@@ -0,0 +1,21 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing initiator type: img with srcset attribute</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#dom-performanceresourcetiming-initiatortype"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resource-timing/resources/observe-entry.js"></script>
+<script src="resources/initiator-type-test.js"></script>
+</head>
+<body>
+<img src="/resource-timing/resources/resource_timing_test0.png"
+    srcset="/resource-timing/resources/resource_timing_test0.png?id=srcset 67w"
+    sizes="67px"></img>
+<script>
+  initiator_type_test("resource_timing_test0.png?id=srcset", "img", "<img srcset>");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/initiator-type/img.html b/test/fixtures/wpt/resource-timing/initiator-type/img.html
new file mode 100644
index 00000000000000..8e2d305048ea51
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/initiator-type/img.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing initiator type: img</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#dom-performanceresourcetiming-initiatortype"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resource-timing/resources/observe-entry.js"></script>
+<script src="resources/initiator-type-test.js"></script>
+</head>
+<body>
+<img src="/resource-timing/resources/resource_timing_test0.png"></img>
+<script>
+  initiator_type_test("resource_timing_test0.png", "img", "<img>");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/initiator-type/input.html b/test/fixtures/wpt/resource-timing/initiator-type/input.html
new file mode 100644
index 00000000000000..a46d416671c1c6
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/initiator-type/input.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing initiator type: input</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#dom-performanceresourcetiming-initiatortype"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resource-timing/resources/observe-entry.js"></script>
+<script src="resources/initiator-type-test.js"></script>
+</head>
+<body>
+<input type="image" src="/resource-timing/resources/resource_timing_test0.png">
+<script>
+  initiator_type_test("resource_timing_test0.png", "input", "<input type=image>");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/initiator-type/link.html b/test/fixtures/wpt/resource-timing/initiator-type/link.html
new file mode 100644
index 00000000000000..c49576a8e650bc
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/initiator-type/link.html
@@ -0,0 +1,38 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing initiator type: link</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#dom-performanceresourcetiming-initiatortype"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resource-timing/resources/observe-entry.js"></script>
+<script src="resources/initiator-type-test.js"></script>
+</head>
+<body>
+<link rel="stylesheet" href="/resource-timing/resources/nested.css">
+<link rel="prefetch"
+    href="/resource-timing/resources/resource_timing_test0.css?id=prefetch">
+<link rel="preload" as="style"
+    href="/resource-timing/resources/resource_timing_test0.css?id=preload">
+<link rel="prerender" href="/resource-timing/resources/green.html?id=prerender">
+<link rel="manifest" href="/resource-timing/resources/manifest.json">
+<link rel="modulepreload" href="resources/empty.js?id=modulePreload">
+<script>
+  initiator_type_test("nested.css", "link", "<link>");
+
+  // Verify there are enries for each of nested.css' nested resources.
+  initiator_type_test("resource_timing_test0.css?id=n1", "css", "css resources embedded in css");
+  initiator_type_test("fonts/Ahem.ttf?id=n1", "css", "font resources embedded in css");
+  initiator_type_test("blue.png?id=n1", "css", "image resources embedded in css");
+
+  initiator_type_test("resource_timing_test0.css?id=prefetch", "link", "<link prefetch>");
+  initiator_type_test("resource_timing_test0.css?id=preload", "link", "<link preload>");
+  initiator_type_test("green.html?id=prerender", "link", "<link prerender>");
+  initiator_type_test("manifest.json", "link", "<link manifest>");
+  initiator_type_test("resources/empty.js?id=modulePreload", "other", "module preload");
+</script>
+<ol>This content forces a font to get fetched</ol>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/initiator-type/misc.html b/test/fixtures/wpt/resource-timing/initiator-type/misc.html
new file mode 100644
index 00000000000000..02d01a16336c93
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/initiator-type/misc.html
@@ -0,0 +1,31 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing initiator type: miscellaneous elements</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#dom-performanceresourcetiming-initiatortype"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resource-timing/resources/observe-entry.js"></script>
+<script src="resources/initiator-type-test.js"></script>
+</head>
+<body background="/resource-timing/resources/blue.png?id=body">
+<input type="image" src="/resource-timing/resources/blue.png?id=input">
+<object type="image/png" data="/resource-timing/resources/blue.png?id=object">
+</object>
+<script>
+  navigator.sendBeacon('/resource-timing/resources/empty.py?id=beacon');
+  fetch('/resource-timing/resources/empty.py?id=fetch');
+  const evtSource = new EventSource('/resource-timing/resources/eventsource.py?id=eventsource');
+</script>
+<script>
+  initiator_type_test("blue.png?id=body", "body", "<body background>");
+  initiator_type_test("blue.png?id=input", "input", "<input type='image'>");
+  initiator_type_test("blue.png?id=object", "object", "<object type='image/png'>");
+  initiator_type_test("empty.py?id=beacon", "beacon", "sendBeacon()");
+  initiator_type_test("empty.py?id=fetch", "fetch", "for fetch()");
+  initiator_type_test("eventsource.py?id=eventsource", "other", "new EventSource()");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/initiator-type/picture.html b/test/fixtures/wpt/resource-timing/initiator-type/picture.html
new file mode 100644
index 00000000000000..e384b9e97dbe8b
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/initiator-type/picture.html
@@ -0,0 +1,39 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing initiator type: picture</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#dom-performanceresourcetiming-initiatortype"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resource-timing/resources/observe-entry.js"></script>
+<script src="resources/initiator-type-test.js"></script>
+</head>
+<body>
+<picture>
+  <source srcset="blue.png?id=picture-source" type="image/png" />
+  <img src="blue.png?id=picture-img" />
+</picture>
+<picture>
+  <source srcset="blue.png?id=picture-notsupported-source" type="image/notsupported" />
+  <img src="blue.png?id=picture-notsupported-img" />
+</picture>
+<picture>
+  <img src="blue.png?id=picture-img-src"
+    srcset="blue.png?id=picture-img-srcset"
+    sizes="67px"></img>
+</picture>
+<picture>
+  <img src="blue.png?id=picture-99x-img-src"
+    srcset="blue.png?id=picture-99x-img-srcset 99x"
+    sizes="67px"></img>
+</picture>
+<script>
+  initiator_type_test("blue.png?id=picture-source", "img", "<source> in a <picture>");
+  initiator_type_test("blue.png?id=picture-notsupported-img", "img", "<img> in a <picture>");
+  initiator_type_test("blue.png?id=picture-img-srcset", "img", "<img srcset> in a <picture>");
+  initiator_type_test("blue.png?id=picture-99x-img-src", "img", "<img src> in a <picture>");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/initiator-type/resources/initiator-type-test.js b/test/fixtures/wpt/resource-timing/initiator-type/resources/initiator-type-test.js
new file mode 100644
index 00000000000000..2b1f844376c34f
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/initiator-type/resources/initiator-type-test.js
@@ -0,0 +1,15 @@
+
+if (observe_entry === undefined) {
+  throw new Error("You must include resource-timing/resources/observe-entry.js "
+    + "before including this script.");
+}
+
+// Asserts that, for the given name, there is/will-be a
+// PerformanceResourceTiming entry that has the given 'initiatorType'. The test
+// is labeled according to the given descriptor.
+const initiator_type_test = (entry_name, expected_initiator, descriptor) => {
+  promise_test(async () => {
+    const entry = await observe_entry(entry_name);
+    assert_equals(entry.initiatorType, expected_initiator);
+  }, `The initiator type for ${descriptor} must be '${expected_initiator}'`);
+};
diff --git a/test/fixtures/wpt/resource-timing/initiator-type/script.html b/test/fixtures/wpt/resource-timing/initiator-type/script.html
new file mode 100644
index 00000000000000..dbd6a131decae1
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/initiator-type/script.html
@@ -0,0 +1,26 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing initiator type: script</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#dom-performanceresourcetiming-initiatortype"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resource-timing/resources/observe-entry.js"></script>
+<script src="resources/initiator-type-test.js"></script>
+</head>
+<body>
+<script src="/resource-timing/resources/empty_script.js"></script>
+<script>
+  const async_xhr = new XMLHttpRequest;
+  async_xhr.open('GET', '/resource-timing/resources/blue.png?id=async_xhr',
+    true);
+  async_xhr.send();
+</script>
+<script>
+  initiator_type_test("empty_script.js", "script", "<script>");
+  initiator_type_test("blue.png?id=async_xhr", "xmlhttprequest", "an asynchronous XmlHTTPRequest");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/initiator-type/style.html b/test/fixtures/wpt/resource-timing/initiator-type/style.html
new file mode 100644
index 00000000000000..051496b766f91b
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/initiator-type/style.html
@@ -0,0 +1,45 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing initiator type: style</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#dom-performanceresourcetiming-initiatortype"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resource-timing/resources/observe-entry.js"></script>
+<script src="resources/initiator-type-test.js"></script>
+</head>
+<body>
+<style>
+  iframe {
+    background: url('/resource-timing/resources/blue.png?id=background');
+  }
+  body {
+    cursor: url('/resource-timing/resources/blue.png?id=cursor'), pointer;
+  }
+  ul {
+    list-style-image: url('/resource-timing/resources/blue.png?id=list-style');
+  }
+
+  @font-face {
+    font-family: remoteFontAhem;
+    src: url('/fonts/Ahem.ttf');
+  }
+  .ahem {
+    font-family: remoteFontAhem;
+  }
+</style>
+<iframe>This iframe forces the 'background' resource to be fetched.</iframe>
+<ul>
+  <li>This content forces the 'list-style-image' resource to be fetched.</li>
+</ul>
+<div class="ahem">This content forces the '@font-face' resource to be fetched.</div>
+<script>
+  initiator_type_test("blue.png?id=background", "css", "'background' attributes in <style> elements");
+  initiator_type_test("blue.png?id=cursor", "css", "'cursor' attributes in <style> elements");
+  initiator_type_test("blue.png?id=list-style", "css", "'list-style-image' attributes in <style> elements");
+  initiator_type_test("fonts/Ahem.ttf", "css", "'@font-face' resources");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/initiator-type/svg.html b/test/fixtures/wpt/resource-timing/initiator-type/svg.html
new file mode 100644
index 00000000000000..d92f5935d807ee
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/initiator-type/svg.html
@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing initiator type: svg</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#dom-performanceresourcetiming-initiatortype"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resource-timing/resources/observe-entry.js"></script>
+<script src="resources/initiator-type-test.js"></script>
+</head>
+<body>
+<svg width=200 height=200
+  xmlns="http://www.w3.org/2000/svg"
+  xmlns:xlink="http://www.w3.org/1999/xlink">
+  <image href="/resource-timing/resources/blue.png" height="200" width="200"/>
+</svg>
+<script>
+  initiator_type_test("blue.png", "image", "<image> in an <svg>");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/initiator-type/video.html b/test/fixtures/wpt/resource-timing/initiator-type/video.html
new file mode 100644
index 00000000000000..16f3b3dea5f1e8
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/initiator-type/video.html
@@ -0,0 +1,32 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing initiator type: video</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#dom-performanceresourcetiming-initiatortype"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resource-timing/resources/observe-entry.js"></script>
+<script src="resources/initiator-type-test.js"></script>
+</head>
+<body>
+<video poster="/resource-timing/resources/blue.png?id=poster"></video>
+<video src="/media/test.mp4?id=src" autoplay="true"></video>
+<video autoplay="true">
+  <source src="/media/test.mp4?id=source-mp4" type="video/mp4">
+  <track kind="subtitles" srclang="en" default
+    src="/resource-timing/resources/empty.py?id=track">
+</video>
+<video autoplay="true">
+  <source src="/media/test.ogv?id=source-ogv" type="video/ogg">
+</video>
+<script>
+  initiator_type_test("blue.png?id=poster", "video", "<video poster>");
+  initiator_type_test("media/test.mp4?id=src", "video", "<video src>");
+  initiator_type_test("media/test.mp4?id=source-mp4", "video", "<source src> with type=\"video/mp4\"");
+  initiator_type_test("empty.py?id=track", "track", "<track src>");
+  initiator_type_test("media/test.ogv?id=source-ogv", "video", "<source src> with type=\"video/ogg\"");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/initiator-type/workers.html b/test/fixtures/wpt/resource-timing/initiator-type/workers.html
new file mode 100644
index 00000000000000..3a23ad71a31555
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/initiator-type/workers.html
@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing initiatorType: worker resources</title>
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#dom-performanceresourcetiming-initiatortype"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resource-timing/resources/observe-entry.js"></script>
+<script src="resources/initiator-type-test.js"></script>
+
+</head>
+
+<script>
+  const moduleWorkerURL = 'resources/empty.js?moduleWorker';
+  const workerURL = 'resources/empty.js?worker';
+  new Worker(moduleWorkerURL, {type: "module"});
+  new Worker(workerURL, {type: "classic"});
+  initiator_type_test(workerURL, "other", "classic worker");
+  initiator_type_test(moduleWorkerURL, "other", "module worker");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/input-sequence-of-events.html b/test/fixtures/wpt/resource-timing/input-sequence-of-events.html
new file mode 100644
index 00000000000000..446e24a0bca8a4
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/input-sequence-of-events.html
@@ -0,0 +1,21 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Test the sequence of events when reporting input timing.</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<body>
+<script>
+  async_test(t => {
+    const input = document.createElement('input');
+    input.type = "image";
+    const absoluteURL = new URL('resources/blue.png', location.href).toString();
+    t.add_cleanup(() => input.remove());
+    input.addEventListener('load', t.step_func(() => {
+      assert_equals(performance.getEntriesByName(absoluteURL).length, 1);
+      t.done();
+    }));
+    input.src = absoluteURL;
+    document.body.appendChild(input);
+  }, "An image input element should receive its load event after the ResourceTiming entry is available");
+
+</script>
diff --git a/test/fixtures/wpt/resource-timing/link-sequence-of-events.html b/test/fixtures/wpt/resource-timing/link-sequence-of-events.html
new file mode 100644
index 00000000000000..be9db32cd92968
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/link-sequence-of-events.html
@@ -0,0 +1,30 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Test the sequence of events when reporting link timing.</title>
+<meta name="timeout" content="long">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<body>
+<script>
+  promise_test(async t => {
+    const link = document.createElement('link');
+    const delay = 500;
+    const src = `./resources/import.sub.css?delay=${delay}`
+    const absoluteURL = new URL(src, location.href).toString();
+    new PerformanceObserver(t.step_func(() => {
+      const allPerformanceEntries = performance.getEntriesByType('resource');
+      const linkEntry = allPerformanceEntries.find(e => e.name.includes('import.sub.css'));
+      const importEntry = allPerformanceEntries.find(e => e.name.includes('delay-css'));
+      if (!linkEntry || !importEntry)
+        return;
+      const linkEndTime = linkEntry.startTime + linkEntry.duration;
+      const importEndTime = importEntry.startTime + importEntry.duration;
+      assert_greater_than_equal(importEndTime, linkEndTime + delay, "link load should be done before import load");
+      t.done();
+
+    })).observe({type: 'resource'});
+    link.href = src;
+    link.rel = 'stylesheet';
+    document.head.appendChild(link);
+  }, "test that @imports don't affect link resource timings");
+</script>
diff --git a/test/fixtures/wpt/resource-timing/load-from-mem-cache-transfer-size.html b/test/fixtures/wpt/resource-timing/load-from-mem-cache-transfer-size.html
new file mode 100644
index 00000000000000..3d2d32d6e63bf4
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/load-from-mem-cache-transfer-size.html
@@ -0,0 +1,65 @@
+<!DOCTYPE HTML>
+<html>
+
+<head>
+  <meta charset="utf-8" />
+  <title>This tests transfer size of resource timing when loaded from memory cache.</title>
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+  <script src="resources/entry-invariants.js"></script>
+</head>
+
+<body>
+  <script>
+    function getScript(url) {
+      const script = document.createElement("script");
+      const loaded = new Promise(resolve => {
+        script.onload = script.onerror = resolve;
+      });
+      script.src = url;
+      document.body.appendChild(script);
+      return loaded;
+    }
+    function add_iframe(url) {
+      return new Promise(function (resolve) {
+        var frame = document.createElement('iframe');
+        frame.src = url;
+        frame.onload = function () { resolve(frame); };
+        document.body.appendChild(frame);
+      });
+    }
+    promise_test(async t => {
+      // Add unique token to url so that each run the url is different to avoid
+      // flakiness.
+      let url = 'resources/resource_timing_test0.js?unique=' +
+        Math.random().toString().substr(2);
+      let frame;
+      return add_iframe('resources/iframe-load-from-mem-cache-transfer-size.html')
+        .then((f) => {
+          frame = f;
+          // Load script onto iframe in order to get it into the memory cache.
+          return frame.contentWindow.getScript(url.split('/')[1])
+        })
+        .then(() => {
+          // Verify that the transferSize in case of normal load is greater than
+          // 0.
+          assert_positive_(
+            frame.contentWindow.performance.getEntriesByType('resource')
+              .filter(e => e.name.includes(url))[0], ['transferSize']);
+
+          // Load the same script onto the parent document. This time the script
+          // is coming from memory cache.
+          return getScript(url);
+        })
+        .then(() => {
+          // Verify that the transferSize in case of memory cache load is 0.
+          assert_zeroed_(
+            window.performance.getEntriesByType('resource')
+              .filter(e => e.name.includes(url))[0], ['transferSize']);
+        });
+    }, "The transferSize of resource timing entries should be 0 when resource \
+    is loaded from memory cache.");
+  </script>
+</body>
+
+</html>
diff --git a/test/fixtures/wpt/resource-timing/nested-context-navigations-embed.html b/test/fixtures/wpt/resource-timing/nested-context-navigations-embed.html
new file mode 100644
index 00000000000000..f804adbb8a99e4
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/nested-context-navigations-embed.html
@@ -0,0 +1,36 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<meta name=timeout content=long>
+<title>Resource Timing embed navigate - back button navigation</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<script src="resources/nested-contexts.js"></script>
+<script>
+  open_test_window("resources/embed-navigate-back.html",
+    "Test that embed navigations are not observable by the parent, even " +
+    "after history navigations by the parent");
+  open_test_window("resources/embed-navigate-back.html?crossorigin",
+    "Test that crossorigin embed navigations are not observable by the " +
+    "parent, even after history navigations by the parent");
+  open_test_window("resources/embed-navigate-back.html?cross-site",
+    "Test that cross-site embed navigations are not observable by the " +
+    "parent, even after history navigations by the parent");
+
+  open_test_window("resources/embed-navigate.html",
+    "Test that embed navigations are not observable by the parent");
+  open_test_window("resources/embed-navigate.html?crossorigin",
+    "Test that crossorigin embed navigations are not observable by the parent");
+  open_test_window("resources/embed-navigate.html?cross-site",
+    "Test that cross-site embed navigations are not observable by the parent");
+  open_test_window("resources/embed-refresh.html",
+    "Test that embed refreshes are not observable by the parent");
+  open_test_window("resources/embed-refresh.html?crossorigin",
+    "Test that crossorigin embed refreshes are not observable by the parent");
+  open_test_window("resources/embed-refresh.html?cross-site",
+    "Test that cross-site embed refreshes are not observable by the parent");
+
+</script>
+
diff --git a/test/fixtures/wpt/resource-timing/nested-context-navigations-iframe.html b/test/fixtures/wpt/resource-timing/nested-context-navigations-iframe.html
new file mode 100644
index 00000000000000..32ab21633c669c
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/nested-context-navigations-iframe.html
@@ -0,0 +1,32 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<meta name=timeout content=long>
+<title>Resource Timing embed navigate - back button navigation</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<script src="resources/nested-contexts.js"></script>
+<script>
+  open_test_window("resources/iframe-navigate-back.html",
+    "Test that iframe navigations are not observable by the parent, even after history navigations by the parent");
+  open_test_window("resources/iframe-navigate-back.html?crossorigin",
+    "Test that crossorigin iframe navigations are not observable by the parent, even after history navigations by the parent");
+  open_test_window("resources/iframe-navigate-back.html?cross-site",
+    "Test that cross-site iframe navigations are not observable by the parent, even after history navigations by the parent");
+  open_test_window("resources/iframe-navigate.html",
+    "Test that iframe navigations are not observable by the parent");
+  open_test_window("resources/iframe-navigate.html?crossorigin",
+    "Test that crossorigin iframe navigations are not observable by the parent");
+  open_test_window("resources/iframe-navigate.html?cross-site",
+    "Test that cross-site iframe navigations are not observable by the parent");
+  open_test_window("resources/iframe-refresh.html",
+    "Test that iframe refreshes are not observable by the parent");
+  open_test_window("resources/iframe-refresh.html?crossorigin",
+    "Test that crossorigin iframe refreshes are not observable by the parent");
+  open_test_window("resources/iframe-refresh.html?cross-site",
+    "Test that cross-site iframe refreshes are not observable by the parent");
+
+</script>
+
diff --git a/test/fixtures/wpt/resource-timing/nested-context-navigations-object.html b/test/fixtures/wpt/resource-timing/nested-context-navigations-object.html
new file mode 100644
index 00000000000000..1508d8829fd269
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/nested-context-navigations-object.html
@@ -0,0 +1,37 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<meta name=timeout content=long>
+<title>Resource Timing embed navigate - back button navigation</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<script src="resources/nested-contexts.js"></script>
+<script>
+  open_test_window("resources/object-navigate-back.html",
+    "Test that object navigations are not observable by the parent, even " +
+    "after history navigations by the parent");
+  open_test_window("resources/object-navigate-back.html?crossorigin",
+    "Test that crossorigin object navigations are not observable by the " +
+    "parent, even after history navigations by the parent");
+  open_test_window("resources/object-navigate-back.html?cross-site",
+    "Test that cross-site object navigations are not observable by the " +
+    "parent, even after history navigations by the parent");
+  open_test_window("resources/object-navigate.html",
+    "Test that object navigations are not observable by the parent");
+  open_test_window("resources/object-navigate.html?crossorigin",
+    "Test that crossorigin object navigations are not observable by the " +
+    "parent");
+  open_test_window("resources/object-navigate.html?cross-site",
+    "Test that cross-site object navigations are not observable by the " +
+    "parent");
+  open_test_window("resources/object-refresh.html",
+    "Test that object refreshes are not observable by the parent");
+  open_test_window("resources/object-refresh.html?crossorigin",
+    "Test that crossorigin object refreshes are not observable by the parent");
+  open_test_window("resources/object-refresh.html?cross-site",
+    "Test that cross-site object refreshes are not observable by the parent");
+
+</script>
+
diff --git a/test/fixtures/wpt/resource-timing/nextHopProtocol-is-tao-protected.https.html b/test/fixtures/wpt/resource-timing/nextHopProtocol-is-tao-protected.https.html
new file mode 100644
index 00000000000000..b16ff7af75dc7a
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/nextHopProtocol-is-tao-protected.https.html
@@ -0,0 +1,49 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing - Check that nextHopProtocol is TAO protected</title>
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#sec-performanceresourcetiming"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/custom-cors-response.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<script src="resources/entry-invariants.js"></script>
+<script src="resources/resource-loaders.js"></script>
+<script src="resources/tao-response.js"></script>
+</head>
+<body>
+<script>
+
+const {HTTPS_REMOTE_ORIGIN} = get_host_info();
+
+const tao_protected_next_hop_test = (loader, item) => {
+  attribute_test(
+    loader, custom_cors_response({}, HTTPS_REMOTE_ORIGIN),
+    entry => assert_equals(entry.nextHopProtocol, "",
+      "nextHopProtocol should be the empty string."),
+    `Fetch TAO-less ${item} from remote origin. Make sure nextHopProtocol ` +
+    "is the empty string."
+  );
+
+  attribute_test(
+    loader, remote_tao_response('*'),
+    entry => assert_not_equals(entry.nextHopProtocol, "",
+      "nextHopProtocol should not be the empty string."),
+    `Fetch TAO'd ${item} from remote origin. Make sure nextHopProtocol ` +
+    "is not the empty string."
+  );
+}
+
+tao_protected_next_hop_test(load.font, "font");
+tao_protected_next_hop_test(load.iframe, "iframe");
+tao_protected_next_hop_test(load.image, "image");
+tao_protected_next_hop_test(path => load.object(path, "text/plain"), "object");
+tao_protected_next_hop_test(load.script, "script");
+tao_protected_next_hop_test(load.stylesheet, "stylesheet");
+tao_protected_next_hop_test(load.xhr_sync, "synchronous xhr");
+tao_protected_next_hop_test(load.xhr_async, "asynchronous xhr");
+
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/no-entries-for-cross-origin-css-fetched.sub.html b/test/fixtures/wpt/resource-timing/no-entries-for-cross-origin-css-fetched.sub.html
new file mode 100644
index 00000000000000..63f9e06e19083a
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/no-entries-for-cross-origin-css-fetched.sub.html
@@ -0,0 +1,39 @@
+<!DOCTYPE HTML>
+<meta charset=utf-8>
+<title>Make sure that resources fetched by cross origin CSS are not in the timeline.</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<body>
+<script>
+    const host = get_host_info();
+
+    const link = document.createElement("LINK");
+    link.rel = "stylesheet";
+    link.id = "cross_origin_style";
+
+    /*
+        This stylesheet is fetched from one of:
+            //www1.web–platform.test:64941/resource-timing/resources/nested.css
+            //127.0.0.1:64941/resource-timing/resources/nested.css
+     */
+    link.href = "//" + host.REMOTE_HOST + ":{{ports[http][1]}}{{location[path]}}/../resources/nested.css"
+    document.currentScript.parentNode.insertBefore(link, document.currentScript);
+</script>
+<script>
+  const t = async_test("Make sure that resources fetched by cross origin CSS are not in the timeline.");
+  window.addEventListener("load", function() {
+    // A timeout is needed as entries are not guaranteed to be in the timeline before onload triggers.
+    t.step_timeout(function() {
+          const url = (new URL(document.getElementById("cross_origin_style").href));
+          const prefix = url.protocol + "//" + url.host;
+          assert_equals(performance.getEntriesByName(prefix + "/resource-timing/resources/resource_timing_test0.css?id=n1").length, 0, "Import should not be in timeline");
+          assert_equals(performance.getEntriesByName(prefix + "/fonts/Ahem.ttf?id=n1").length, 0, "Font should not be in timeline");
+          assert_equals(performance.getEntriesByName(prefix + "/resource-timing/resources/blue.png?id=n1").length, 0, "Image should not be in timeline");
+          t.done();
+    }, 200);
+  });
+</script>
+<ol>Some content</ol>
+</body>
+
diff --git a/test/fixtures/wpt/resource-timing/object-not-found-adds-entry.html b/test/fixtures/wpt/resource-timing/object-not-found-adds-entry.html
new file mode 100644
index 00000000000000..d11823dd9d07f5
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/object-not-found-adds-entry.html
@@ -0,0 +1,37 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>This test validates that object resource emit resource timing entries.</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#sec-performanceresourcetiming"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/entry-invariants.js"></script>
+<script src="resources/resource-loaders.js"></script>
+</head>
+<body>
+<script>
+const load_image_object = async path => {
+  return load.object(path, "image/png");
+}
+
+const load_null_object = async path => {
+  return load.object(path, null);
+}
+
+attribute_test(
+  load_null_object, "resources/status-code.py?status=200&type=none",
+  invariants.assert_tao_pass_no_redirect_http,
+  "Verify that a 200 null-typed object emits an entry.");
+
+attribute_test(
+  load_null_object, "resources/status-code.py?status=404&type=none",
+  invariants.assert_tao_pass_no_redirect_http,
+  "Verify that a 404 null-typed object emits an entry.");
+
+attribute_test(
+  load_image_object, "resources/status-code.py?status=404&type=img",
+  invariants.assert_tao_pass_no_redirect_http,
+  "Verify that a 404 img-typed object emits an entry.");
+</script>
diff --git a/test/fixtures/wpt/resource-timing/object-not-found-after-TAO-cross-origin-redirect.html b/test/fixtures/wpt/resource-timing/object-not-found-after-TAO-cross-origin-redirect.html
new file mode 100644
index 00000000000000..d0dad9381ba42b
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/object-not-found-after-TAO-cross-origin-redirect.html
@@ -0,0 +1,47 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>This test validates resource timing information for a timing allowed cross-origin redirect chain.</title>
+<link rel="help" href="http://www.w3.org/TR/resource-timing/#performanceresourcetiming"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src=/common/get-host-info.sub.js></script>
+<script src="resources/webperftestharness.js"></script>
+<script src="resources/webperftestharnessextension.js"></script>
+
+<script>
+    setup({explicit_done: true});
+    test_namespace('getEntriesByName');
+
+    function onload_test()
+    {
+        const context = new PerformanceContext(performance);
+        const entries = context.getEntriesByName(document.querySelector('object').data, 'resource');
+        test_equals(entries.length, 1, 'There should be one entry.');
+        const entry = entries[0];
+
+        test_greater_than(entry.redirectStart, 0, 'redirectStart > 0 in timing allowed cross-origin redirect.');
+        test_equals(entry.redirectStart, entry.startTime, 'redirectStart == startTime in timing allowed cross-origin redirect.');
+        test_greater_than(entry.redirectEnd, entry.redirectStart, 'redirectEnd > redirectStart in timing allowed cross-origin redirect.');
+        test_greater_or_equals(entry.fetchStart, entry.redirectEnd, 'fetchStart >= redirectEnd in timing allowed cross-origin redirect.');
+        done();
+    }
+</script>
+
+</head>
+<body>
+<script>
+    let destUrl = get_host_info().HTTP_REMOTE_ORIGIN + '/resource-timing/resources/multi_redirect.py?';
+    destUrl += 'page_origin=' + 'http://' + document.location.host;
+    destUrl += '&cross_origin=' + get_host_info().HTTP_REMOTE_ORIGIN;
+    destUrl += '&final_resource=' + encodeURIComponent("/resource-timing/resources/status-code.py?status=404&tao_value=*");
+    destUrl += '&tao_steps=3';
+    const objElement = document.createElement('object');
+    objElement.style = 'width: 0px; height: 0px;';
+    objElement.data = destUrl;
+    objElement.onerror = onload_test;
+    document.body.appendChild(objElement);
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/object-not-found-after-cross-origin-redirect.html b/test/fixtures/wpt/resource-timing/object-not-found-after-cross-origin-redirect.html
new file mode 100644
index 00000000000000..278c78e320e98c
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/object-not-found-after-cross-origin-redirect.html
@@ -0,0 +1,35 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>This test validates the values in resource timing for cross-origin
+redirects.</title>
+<link rel="author" title="Noam Rosenthal" href="noam@webkit.org">
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#sec-performanceresourcetiming"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<script src="resources/resource-loaders.js"></script>
+<script src="resources/entry-invariants.js"></script>
+</head>
+<body>
+<script>
+const {REMOTE_ORIGIN} = get_host_info();
+const delay = 2
+const not_found_page = encodeURIComponent("/resource-timing/resources/status-code.py?status=404");
+const load_null_object = async path => {
+  return load.object(path, null);
+}
+const destUrl = `/common/slow-redirect.py?delay=${delay}&location=${REMOTE_ORIGIN}/${not_found_page}`;
+
+const timeBefore = performance.now()
+attribute_test(load_null_object, destUrl, entry => {
+    assert_equals(entry.startTime, entry.fetchStart, 'startTime and fetchStart should be equal');
+    assert_greater_than(entry.startTime, timeBefore, 'startTime and fetchStart should be greater than the time before fetching');
+    // See https://github.com/w3c/resource-timing/issues/264
+    assert_less_than(Math.round(entry.startTime - timeBefore), delay * 1000, 'startTime should not expose redirect delays');
+}, "Verify that cross-origin object resources don't implicitly expose their redirect timings")
+
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/opaque-origin.html b/test/fixtures/wpt/resource-timing/opaque-origin.html
new file mode 100644
index 00000000000000..598ee50a59278f
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/opaque-origin.html
@@ -0,0 +1,46 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing TAO - "null" and opaque origin</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#timing-allow-origin"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+</head>
+<body>
+<h1>Description</h1>
+<p>This test validates that, for a cross origin resource, the timing allow
+check algorithm will correctly distinguish between 'null' and 'Null' values in
+the Timing-Allow-Origin header. An opaque origin's serialization is the string
+"null" and the timing allow origin check needs to do a case-sensitive comparison
+to the Timing-Allow-Origin header.
+</p>
+<iframe id="frameContext"></iframe>
+<script>
+const {ORIGIN} = get_host_info();
+const url = `${ORIGIN}/resource-timing/resources/TAOResponse.py`;
+const frame_content = `data:text/html;utf8,<body>
+  <script src="${ORIGIN}/resources/testharness.js"></` + `script>
+  <script src="${ORIGIN}/resource-timing/resources/entry-invariants.js">
+  </` + `script>
+  <script>
+    attribute_test(fetch, "${url}?tao=null",
+      invariants.assert_tao_pass_no_redirect_http,
+      "An opaque origin should be authorized to see resource timings when the" +
+      "TAO header is the string 'null'");
+    attribute_test(fetch, "${url}?tao=Null",
+      invariants.assert_tao_failure_resource,
+      "An opaque origin must not be authorized to see resource timings when " +
+      "the TAO header is the string 'Null'. (The check for 'null' must be " +
+      "case-sensitive)");
+  </` + `script>
+</body>`;
+
+frameContext.style = "display:none";
+frameContext.src = frame_content;
+fetch_tests_from_window(frameContext.contentWindow);
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/ping-rt-entries.html b/test/fixtures/wpt/resource-timing/ping-rt-entries.html
new file mode 100644
index 00000000000000..34dad10b9f28b6
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/ping-rt-entries.html
@@ -0,0 +1,29 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing Entry For hyperlink audit (ping)</title>
+<link rel="help" href="https://w3c.github.io/resource-timing/"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resource-timing/resources/observe-entry.js"></script>
+</head>
+<body>
+<script>
+    promise_test(async t => {
+        const link = document.createElement('a');
+        const delay = 500;
+        const ping = `/xhr/resources/delay.py?ms=${delay}`;
+        link.setAttribute('href', 'resources/close.html');
+        link.setAttribute('target', '_blank');
+        link.setAttribute('ping', ping);
+        link.innerText = 'Link';
+        document.body.appendChild(link);
+        link.click();
+        const entry = await observe_entry(ping);
+        assert_equals(entry.initiatorType, 'ping');
+        assert_greater_than(entry.duration, delay);
+    }, "Hyperlink auditing (<a ping>) should have a resource timing entry");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/redirects.html b/test/fixtures/wpt/resource-timing/redirects.html
new file mode 100644
index 00000000000000..ba69907a5f6e46
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/redirects.html
@@ -0,0 +1,61 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing: resources fetched through same-origin redirects</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#sec-performanceresourcetiming"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<script src="resources/resource-loaders.js"></script>
+<script src="resources/entry-invariants.js"></script>
+<script>
+const {HTTPS_NOTSAMESITE_ORIGIN} = get_host_info();
+const redirect_url = `/common/redirect.py`;
+const url_prefix = `${redirect_url}?location=/resource-timing/resources/`;
+const https_url_prefix = `${redirect_url}?location=${HTTPS_NOTSAMESITE_ORIGIN}/resource-timing/resources/`;
+
+attribute_test(
+  load.stylesheet, url_prefix + "resource_timing_test0.css",
+  invariants.assert_same_origin_redirected_resource,
+  "Verify attributes of a redirected stylesheet's PerformanceResourceTiming");
+
+attribute_test(
+  load.image, url_prefix + "blue.png",
+  invariants.assert_same_origin_redirected_resource,
+  "Verify attributes of a redirected image's PerformanceResourceTiming");
+
+attribute_test(
+  load.iframe, url_prefix + "green.html",
+  invariants.assert_same_origin_redirected_resource,
+  "Verify attributes of a redirected iframe's PerformanceResourceTiming");
+
+attribute_test(
+  load.script, url_prefix + "empty_script.js",
+  invariants.assert_same_origin_redirected_resource,
+  "Verify attributes of a redirected script's PerformanceResourceTiming");
+
+attribute_test(
+  load.xhr_sync, url_prefix + "green.html?id=xhr",
+  invariants.assert_same_origin_redirected_resource,
+  "Verify attributes of a redirected synchronous XMLHttpRequest's " +
+  "PerformanceResourceTiming");
+
+attribute_test(
+  load.xhr_sync, https_url_prefix + "green.html?id=xhr",
+  invariants.assert_cross_origin_redirected_resource,
+  "Verify attributes of a synchronous XMLHttpRequest's " +
+  "PerformanceResourceTiming where the initial HTTP request is redirected " +
+  "to a cross-origin HTTPS resource."
+);
+
+</script>
+</head>
+<body>
+<h1>Description</h1>
+<p>This test validates that, when a fetching resources that encounter
+same-origin redirects, attributes of the PerformanceResourceTiming entry
+conform to the specification.</p>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/render-blocking-status-link.html b/test/fixtures/wpt/resource-timing/render-blocking-status-link.html
new file mode 100644
index 00000000000000..8c6544db48664e
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/render-blocking-status-link.html
@@ -0,0 +1,222 @@
+<!DOCTYPE html>
+<head>
+<meta charset="utf-8" />
+<title>This test validates the render blocking status of resources.</title>
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#sec-performanceresourcetiming"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<!-- Start of test cases -->
+<script>
+    // Dynamic style using document.write in head
+    document.write(`
+        <link rel=stylesheet
+              href='resources/empty_style.css?stylesheet-head-dynamic-docWrite'>
+    `);
+    document.write(`
+        <link rel=stylesheet
+              href='resources/empty_style.css?stylesheet-head-dynamic-docWrite-print'
+              media=print>
+    `);
+</script>
+
+<link rel=stylesheet href="resources/empty_style.css?stylesheet-head">
+<link rel=stylesheet href="resources/empty_style.css?stylesheet-head-media-print"
+      media=print>
+<link rel="alternate stylesheet"
+      href="resources/empty_style.css?stylesheet-head-alternate">
+<link rel=preload as=style href="resources/empty_style.css?link-style-head-preload">
+<link rel=preload as=style href="resources/empty_style.css?link-style-preload-used">
+<link rel=stylesheet href="resources/importer.css?stylesheet-importer-head">
+<link rel=stylesheet id="link-head-remove-attr" blocking="render"
+    href="resources/empty_style.css?stylesheet-head-blocking-render-remove-attr">
+<link rel=modulepreload href="resources/empty_script.js?link-head-modulepreload">
+
+<style>@import url(resources/empty_style.css?stylesheet-inline-imported);</style>
+<style media=print>
+    @import url(resources/empty_style.css?stylesheet-inline-imported-print);
+</style>
+</head>
+
+<body>
+
+<link rel=stylesheet href="resources/empty_style.css?stylesheet-body">
+<link rel=stylesheet href="resources/importer.css?stylesheet-importer-body">
+<link rel=stylesheet href="resources/empty_style.css?stylesheet-body-media-print"
+      media=print>
+<link rel=stylesheet blocking="render"
+    href="resources/empty_style.css?stylesheet-body-blocking-render">
+
+<!-- https://html.spec.whatwg.org/multipage/urls-and-fetching.html#blocking-attributes
+     mentions that an element is potentially render-blocking if its blocking
+     tokens set contains "render", or if it is implicitly potentially
+     render-blocking. By default, an element is not implicitly potentially
+     render-blocking.
+     https://html.spec.whatwg.org/multipage/links.html#link-type-stylesheet
+     specifies that a link element of type stylesheet is implicitly potentially
+     render-blocking only if the element was created by its node document's parser. -->
+<script>
+    // Dynamic style using document.write in body
+    document.write(`
+        <link rel=stylesheet
+              href='resources/empty_style.css?stylesheet-body-dynamic-docWrite'>
+    `);
+    document.write(`
+        <link rel=stylesheet
+              href='resources/empty_style.css?stylesheet-body-dynamic-docWrite-print'
+              media=print>
+    `);
+
+    // Dynamic style using innerHTML
+    document.head.innerHTML += `
+        <link rel=stylesheet
+              href='resources/empty_style.css?stylesheet-head-dynamic-innerHTML'>
+    `;
+    document.head.innerHTML += `
+        <link rel=stylesheet
+              href='resources/empty_style.css?stylesheet-head-dynamic-innerHTML-print'
+              media=print>
+    `;
+    document.head.innerHTML += `
+        <link rel=stylesheet blocking=render
+              href='resources/empty_style.css?stylesheet-head-blocking-render-dynamic-innerHTML'>
+    `;
+
+    // Dynamic style using DOM API
+    var link = document.createElement("link");
+    link.href = "resources/empty_style.css?stylesheet-head-dynamic-dom";
+    link.rel = "stylesheet";
+    document.head.appendChild(link);
+
+    // Add a dynamic render-blocking style with DOM API
+    link = document.createElement("link");
+    link.href = "resources/empty_style.css?stylesheet-head-blocking-render-dynamic-dom";
+    link.rel = "stylesheet";
+    link.blocking = "render";
+    document.head.appendChild(link);
+
+    // Dynamic style preload using DOM API
+    link = document.createElement("link");
+    link.href = "resources/empty_style.css?link-style-head-preload-dynamic-dom";
+    link.rel = "preload";
+    link.as = "style";
+    document.head.appendChild(link);
+
+    // Dynamic module via modulepreload using DOM API
+    link = document.createElement("link");
+    link.href = "resources/empty_script.js?link-head-modulepreload-dynamic-dom";
+    link.rel = "modulepreload";
+    document.head.appendChild(link);
+
+    // Add a style preload with DOM API to be used later
+    link = document.createElement("link");
+    link.href = "resources/empty_style.css?link-style-preload-used-dynamic";
+    link.rel = "preload";
+    link.as = "style";
+    document.head.appendChild(link);
+    // Use the preload
+    link = document.createElement("link");
+    link.href = "resources/empty_style.css?link-style-preload-used-dynamic";
+    link.rel = "stylesheet";
+    document.head.appendChild(link);
+
+    // Dynamic inline CSS
+    // Add an inline CSS importer
+    document.write(`
+        <style>
+            @import url('resources/empty_style.css?stylesheet-inline-imported-dynamic-docwrite')
+        </style>
+    `);
+    document.write(`
+        <style media=print>
+            @import url('resources/empty_style.css?stylesheet-inline-imported-dynamic-docwrite-print')
+        </style>
+    `);
+
+    // Add a dynamic inline CSS importer using DOM API
+    let style = document.createElement("style");
+    style.textContent = "@import url('resources/empty_style.css?stylesheet-inline-imported-dynamic-dom')";
+    document.head.appendChild(style);
+
+    // Add a dynamic render-blocking inline CSS importer
+    style = document.createElement("style");
+    style.textContent = "@import url('resources/empty_style.css?stylesheet-inline-imported-blocking-render-dynamic-dom')";
+    style.blocking = "render";
+    document.head.appendChild(style);
+
+    // Dynamic CSS importer
+    document.write(`
+        <link rel=stylesheet href='resources/importer_dynamic.css'>
+    `);
+    document.write(`
+        <link rel=stylesheet href='resources/importer_print.css' media=print>
+    `);
+
+    // Removing blocking render attribute after request is made
+    const sheet = document.getElementById("link-head-remove-attr");
+    sheet.blocking = "";
+</script>
+
+<link rel=stylesheet href="resources/empty_style.css?link-style-preload-used">
+
+<script>
+
+const wait_for_onload = () => {
+  return new Promise(resolve => {
+    window.addEventListener("load", resolve);
+})};
+
+promise_test(
+  async () => {
+    const expectedRenderBlockingStatus = {
+        'stylesheet-head-dynamic-docWrite': 'blocking',
+        'stylesheet-head-dynamic-docWrite-print': 'non-blocking',
+        'stylesheet-head': 'blocking',
+        'stylesheet-head-media-print' : 'non-blocking',
+        'stylesheet-head-alternate' : 'non-blocking',
+        'link-style-head-preload' : 'non-blocking',
+        'stylesheet-importer-head' : 'blocking',
+        'stylesheet-head-blocking-render-remove-attr' : 'blocking',
+        'link-head-modulepreload' : 'non-blocking',
+        'stylesheet-inline-imported' : 'blocking',
+        'stylesheet-inline-imported-print' : 'non-blocking',
+        'stylesheet-body': 'non-blocking',
+        'stylesheet-importer-body' : 'non-blocking',
+        'stylesheet-body-media-print' : 'non-blocking',
+        'stylesheet-body-blocking-render' : 'non-blocking',
+        'stylesheet-body-dynamic-docWrite' : 'non-blocking',
+        'stylesheet-body-dynamic-docWrite-print': 'non-blocking',
+        'stylesheet-head-dynamic-innerHTML' : 'non-blocking',
+        'stylesheet-head-dynamic-innerHTML-print' : 'non-blocking',
+        'stylesheet-head-blocking-render-dynamic-innerHTML' : 'blocking',
+        'stylesheet-head-dynamic-dom' : 'non-blocking',
+        'stylesheet-head-blocking-render-dynamic-dom' : 'blocking',
+        'link-style-head-preload-dynamic-dom' : 'non-blocking',
+        'link-head-modulepreload-dynamic-dom' : 'non-blocking',
+        'link-style-preload-used' : 'non-blocking',
+        'link-style-preload-used-dynamic' : 'non-blocking',
+        'stylesheet-inline-imported-dynamic-docwrite': 'blocking',
+        'stylesheet-inline-imported-dynamic-docwrite-print' : 'non-blocking',
+        'stylesheet-inline-imported-dynamic-dom' : 'non-blocking',
+        'stylesheet-inline-imported-blocking-render-dynamic-dom' : 'blocking',
+        'stylesheet-imported' : 'blocking',
+        'stylesheet-imported-print' : 'non-blocking',
+        'stylesheet-imported-dynamic' : 'non-blocking'
+    };
+
+    await wait_for_onload();
+
+    const entry_list = performance.getEntriesByType("resource");
+    for (entry of entry_list) {
+        if (entry.name.includes("empty_style.css") ||
+                entry.name.includes("importer.css") ||
+                entry.name.includes("empty_script.js")) {
+            key = entry.name.split("?").pop();
+            expectedStatus = expectedRenderBlockingStatus[key];
+            assert_equals(entry.renderBlockingStatus, expectedStatus,
+                `render blocking status for ${entry.name} should be ${expectedStatus}`);
+        }
+    }
+}, "Validate render blocking status of link resources in PerformanceResourceTiming");
+
+</script>
\ No newline at end of file
diff --git a/test/fixtures/wpt/resource-timing/render-blocking-status-script.html b/test/fixtures/wpt/resource-timing/render-blocking-status-script.html
new file mode 100644
index 00000000000000..bcd55b89944fc6
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/render-blocking-status-script.html
@@ -0,0 +1,196 @@
+<!DOCTYPE html>
+<head>
+<meta charset="utf-8" />
+<title>This test validates the render blocking status of resources.</title>
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#sec-performanceresourcetiming"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<!-- Start of test cases -->
+<script src="resources/empty_script.js?script-head"></script>
+<script type="module" src="resources/empty_script.js?script-head-module"></script>
+<script async type=module
+        src="resources/empty_script.js?script-head-async-module">
+</script>
+<script async src="resources/empty_script.js?script-head-async"></script>
+<script defer src="resources/empty_script.js?script-head-defer"></script>
+<script blocking=render
+        src="resources/empty_script.js?script-head-blocking-render">
+</script>
+<script async blocking=render
+        src="resources/empty_script.js?script-head-async-blocking-render">
+</script>
+<script type=module blocking=render
+        src="resources/empty_script.js?script-head-module-blocking-render">
+</script>
+<script async type=module blocking=render
+        src="resources/empty_script.js?script-head-async-module-blocking-render">
+</script>
+<script defer blocking=render
+        src="resources/empty_script.js?script-head-defer-blocking-render">
+</script>
+
+<script id="script-head-remove-attr" blocking=render
+        src="resources/empty_script.js?script-head-blocking-render-remove-attr">
+</script>
+
+<script>
+    document.write(`
+        <script defer
+            src="resources/empty_script.js?script-head-defer-dynamic-docwrite">
+        <\/script>`);
+</script>
+</head>
+
+<body>
+
+<script src="resources/empty_script.js?script-body"></script>
+<script type="module" src="resources/empty_script.js?script-body-module"></script>
+<script async type=module
+        src="resources/empty_script.js?script-body-async-module">
+</script>
+<script async src="resources/empty_script.js?script-body-async"></script>
+<script defer src="resources/empty_script.js?script-body-defer"></script>
+
+<script>
+    const script = document.createElement("script");
+    script.src = "resources/empty_script.js?script-head-dynamic-dom";
+    document.head.appendChild(script);
+
+    // Dynamic explicitly async script
+    const async_script = document.createElement("script");
+    async_script.src = "resources/empty_script.js?script-head-async-dynamic-dom";
+    async_script.async = true;
+    document.head.appendChild(async_script);
+
+    // Dynamic non-async script
+    // https://html.spec.whatwg.org/multipage/scripting.html#script-processing-model
+    // mentions that a script element has to be parser-inserted to be
+    // implicitly potentially render-blocking
+    const non_async_script = document.createElement("script");
+    non_async_script.src = "resources/empty_script.js?script-head-non-async-dynamic-dom";
+    non_async_script.async = false;
+    document.head.appendChild(non_async_script);
+
+    // Dynamic defer script
+    const defer_script = document.createElement("script");
+    defer_script.src = "resources/empty_script.js?script-head-defer-dynamic-dom";
+    defer_script.defer = true;
+    document.head.appendChild(defer_script);
+
+    // Dynamic explicitly render-blocking script
+    const blocking_script = document.createElement("script");
+    blocking_script.src = "resources/empty_script.js?script-head-blocking-render-dynamic-dom";
+    blocking_script.blocking = "render";
+    document.head.appendChild(blocking_script);
+
+    // Dynamic explicitly render-blocking module script
+    const blocking_module_script = document.createElement("script");
+    blocking_module_script.src = "resources/empty_script.js?script-head-module-blocking-render-dynamic-dom";
+    blocking_module_script.type = "module";
+    blocking_module_script.blocking = "render";
+    document.head.appendChild(blocking_module_script);
+
+    // Dynamic async module script
+    const async_module_script = document.createElement("script");
+    async_module_script.src = "resources/empty_script.js?script-head-async-module-dynamic-dom";
+    async_module_script.type = "module";
+    async_module_script.async = true;
+    document.head.appendChild(async_module_script);
+
+    // Dynamic async render-blocking module script
+    const async_blocking_module_script = document.createElement("script");
+    async_blocking_module_script.src = "resources/empty_script.js?script-head-async-module-blocking-render-dynamic-dom";
+    async_blocking_module_script.type = "module";
+    async_blocking_module_script.async = true;
+    async_blocking_module_script.blocking = "render"
+    document.head.appendChild(async_blocking_module_script);
+
+    // Add a module that imports more modules
+    const importer_script = document.createElement("script");
+    importer_script.src = "resources/fake_responses.py?url=importer.js";
+    importer_script.type = "module";
+    document.head.appendChild(importer_script);
+
+    // Add an async module that imports more modules
+    const importer_async_script = document.createElement("script");
+    importer_async_script.src = "resources/fake_responses.py?url=importer_async.js";
+    importer_async_script.type = "module";
+    importer_async_script.async = true;
+    document.head.appendChild(importer_async_script);
+
+    // Removing blocking render attribute after request is made
+    const script_element = document.getElementById("script-head-remove-attr");
+    script_element.blocking = "";
+</script>
+
+
+<script>
+
+const wait_for_onload = () => {
+  return new Promise(resolve => {
+    window.addEventListener("load", resolve);
+})};
+
+promise_test(
+  async () => {
+    const expectedRenderBlockingStatus = {
+        'script-head': 'blocking',
+        'script-head-module' : 'non-blocking',
+        'script-head-async-module' : 'non-blocking',
+        'script-head-async' : 'non-blocking',
+        'script-head-defer' : 'non-blocking',
+        'script-head-blocking-render' : 'blocking',
+        'script-head-async-blocking-render' : 'blocking',
+        'script-head-module-blocking-render' : 'blocking',
+        'script-head-async-module-blocking-render' : 'blocking',
+        'script-head-defer-blocking-render' : 'blocking',
+        'script-head-blocking-render-remove-attr' : 'blocking',
+        'script-head-defer-dynamic-docwrite' : 'non-blocking',
+        'script-body' : 'non-blocking',
+        'script-body-module' : 'non-blocking',
+        'script-body-async-module' : 'non-blocking',
+        'script-body-async' : 'non-blocking',
+        'script-body-defer' : 'non-blocking',
+        'script-head-dynamic-dom': 'non-blocking',
+        'script-head-async-dynamic-dom' : 'non-blocking',
+        'script-head-non-async-dynamic-dom': 'non-blocking',
+        'script-head-defer-dynamic-dom' : 'non-blocking',
+        'script-head-blocking-render-dynamic-dom' : 'blocking',
+        'script-head-module-blocking-render-dynamic-dom' : 'blocking',
+        'script-head-async-module-dynamic-dom' : 'non-blocking',
+        'script-head-async-module-blocking-render-dynamic-dom' : 'blocking',
+        'script-head-import-defer' : 'non-blocking',
+        'script-head-import-defer-dynamic' : 'non-blocking',
+        'script-head-import-async' : 'non-blocking',
+        'script-head-import-async-dynamic' : 'non-blocking',
+        'script-importer' : 'non-blocking',
+        'script-importer-async' : 'non-blocking'
+    };
+
+    await wait_for_onload();
+
+    const entry_list = performance.getEntriesByType("resource");
+    for (entry of entry_list) {
+        if (entry.name.includes("empty_script.js")) {
+            key = entry.name.split("?").pop();
+            expectedStatus = expectedRenderBlockingStatus[key];
+            assert_equals(entry.renderBlockingStatus, expectedStatus,
+                `render blocking status for ${entry.name} should be ${expectedStatus}`);
+        }
+        else if (entry.name.includes("importer.js")){
+            key = 'script-importer';
+            expectedStatus = expectedRenderBlockingStatus[key];
+            assert_equals(entry.renderBlockingStatus, expectedStatus,
+                `render blocking status for ${entry.name} should be ${expectedStatus}`);
+        }
+        else if (entry.name.includes("importer_async.js")){
+            key = 'script-importer-async';
+            expectedStatus = expectedRenderBlockingStatus[key];
+            assert_equals(entry.renderBlockingStatus, expectedStatus,
+                `render blocking status for ${entry.name} should be ${expectedStatus}`);
+        }
+    }
+}, "Validate render blocking status of script resources in PerformanceResourceTiming");
+
+</script>
\ No newline at end of file
diff --git a/test/fixtures/wpt/resource-timing/resource-ignore-data-url.html b/test/fixtures/wpt/resource-timing/resource-ignore-data-url.html
new file mode 100644
index 00000000000000..a7056a80807967
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resource-ignore-data-url.html
@@ -0,0 +1,39 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing ignores resources with data: URIs</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#resources-included-in-the-performanceresourcetiming-interface"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/resource-loaders.js"></script>
+</head>
+<body>
+<img src="data:image/gif;base64,R0lGODlhAQABAIAAAOTm7AAAACH5BAEAAAAALAAAAAABAAEAAAICRAEAOw=="></img>
+<script>
+  promise_test(async t => {
+    const promise = new Promise(resolve => {
+      new PerformanceObserver(t.step_func(list => {
+        const entries = list.getEntries();
+        const dataEntries = entries.filter(e => e.name.includes('data:'));
+        assert_equals(dataEntries.length, 0, 'There must be no entry for `data: URL`.');
+        const blueEntries = entries.filter(e => e.name.includes('blue.png'));
+        if (blueEntries.length) {
+          // We can finish the test once we see the entry with blue.png.
+          resolve();
+        }
+      })).observe({entryTypes: ['resource']});
+    });
+    // Wait until the document is loaded.
+    await new Promise(resolve => {
+      window.addEventListener('load', resolve);
+    });
+    // Add the blue.png image after document is loaded to ensure we've received
+    // all of the previous Resource Timing entries.
+    load.image('blue.png');
+    return promise;
+  }, 'Resources with data: URIs must not be surfaced in Resource Timing');
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/resource-reload-TAO.html b/test/fixtures/wpt/resource-timing/resource-reload-TAO.html
new file mode 100644
index 00000000000000..83a1e921bb4f65
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resource-reload-TAO.html
@@ -0,0 +1,18 @@
+<!doctype html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing - TAO on reload</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#sec-timing-allow-origin"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<iframe id="test_iframe" src="resources/iframe-reload-TAO.html"></iframe>
+<script>
+window.onload = () => {
+  fetch_tests_from_window(test_iframe.contentWindow);
+};
+</script>
+</body>
diff --git a/test/fixtures/wpt/resource-timing/resource-timing-level1.js b/test/fixtures/wpt/resource-timing/resource-timing-level1.js
new file mode 100644
index 00000000000000..95b5cdfb1ed0ca
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resource-timing-level1.js
@@ -0,0 +1,517 @@
+"use strict";
+
+window.onload =
+    function () {
+        setup({ explicit_timeout: true });
+
+        /** Number of milliseconds to delay when the server injects pauses into the response.
+
+            This should be large enough that we can distinguish it from noise with high confidence,
+            but small enough that tests complete quickly. */
+        var serverStepDelay = 250;
+
+        var mimeHtml    = "text/html";
+        var mimeText    = "text/plain";
+        var mimePng     = "image/png";
+        var mimeScript  = "application/javascript";
+        var mimeCss     = "text/css";
+
+        /** Hex encoding of a a 150x50px green PNG. */
+        var greenPng = "0x89504E470D0A1A0A0000000D494844520000006400000032010300000090FBECFD00000003504C544500FF00345EC0A80000000F49444154281563601805A36068020002BC00011BDDE3900000000049454E44AE426082";
+
+        /** Array containing test cases to run.  Initially, it contains the one-off 'about:blank" test,
+            but additional cases are pushed below by expanding templates. */
+        var testCases = [
+            {
+                description: "No timeline entry for about:blank",
+                test:
+                    function (test) {
+                        // Insert an empty IFrame.
+                        var frame = document.createElement("iframe");
+
+                        // Wait for the IFrame to load and ensure there is no resource entry for it on the timeline.
+                        //
+                        // We use the 'createOnloadCallbackFn()' helper which is normally invoked by 'initiateFetch()'
+                        // to avoid setting the IFrame's src.  It registers a test step for us, finds our entry on the
+                        // resource timeline, and wraps our callback function to automatically vet invariants.
+                        frame.onload = createOnloadCallbackFn(test, frame, "about:blank",
+                            function (initiator, entry) {
+                                assert_equals(entry, undefined, "Inserting an IFrame with a src of 'about:blank' must not add an entry to the timeline.");
+                                assertInvariants(
+                                    test,
+                                    function () {
+                                        test.done();
+                                    });
+                            });
+
+                        document.body.appendChild(frame);
+
+                        // Paranoid check that the new IFrame has loaded about:blank.
+                        assert_equals(
+                            frame.contentWindow.location.href,
+                            "about:blank",
+                            "'Src' of new <iframe> must be 'about:blank'.");
+                    }
+            },
+        ];
+
+        // Create cached/uncached tests from the following array of templates.  For each template entry,
+        // we add two identical test cases to 'testCases'.  The first case initiates a fetch to populate the
+        // cache.  The second request initiates a fetch with the same URL to cover the case where we hit
+        // the cache (if the caching policy permits caching).
+        [
+            { initiator: "iframe",         response: "(done)",      mime: mimeHtml },
+            { initiator: "xmlhttprequest", response: "(done)",      mime: mimeText },
+            // Multiple browsers seem to cheat a bit and race onLoad of images.  Microsoft https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/2379187
+            // { initiator: "img",            response: greenPng,      mime: mimePng },
+            { initiator: "script",         response: '"";',         mime: mimeScript },
+            { initiator: "link",           response: ".unused{}",   mime: mimeCss },
+        ]
+        .forEach(function (template) {
+            testCases.push({
+                description: "'" + template.initiator + " (Populate cache): The initial request populates the cache (if appropriate).",
+                test: function (test) {
+                    initiateFetch(
+                        test,
+                        template.initiator,
+                        getSyntheticUrl(
+                            "mime:" + encodeURIComponent(template.mime)
+                                + "&send:" + encodeURIComponent(template.response),
+                            /* allowCaching = */ true),
+                        function (initiator, entry) {
+                            test.done();
+                        });
+                    }
+                });
+
+            testCases.push({
+                description: "'" + template.initiator + " (Potentially Cached): Immediately fetch the same URL, exercising the cache hit path (if any).",
+                test: function (test) {
+                    initiateFetch(
+                        test,
+                        template.initiator,
+                        getSyntheticUrl(
+                            "mime:" + encodeURIComponent(template.mime)
+                                + "&send:" + encodeURIComponent(template.response),
+                            /* allowCaching = */ true),
+                        function (initiator, entry) {
+                            test.done();
+                        });
+                    }
+                });
+            });
+
+        // Create responseStart/responseEnd tests from the following array of templates.  In this test, the server delays before
+        // responding with responsePart1, then delays again before completing with responsePart2.  The test looks for the expected
+        // pauses before responseStart and responseEnd.
+        [
+            { initiator: "iframe",         responsePart1: serverStepDelay + "ms;", responsePart2: (serverStepDelay * 2) + "ms;(done)",                                                      mime: mimeHtml },
+            { initiator: "xmlhttprequest", responsePart1: serverStepDelay + "ms;", responsePart2: (serverStepDelay * 2) + "ms;(done)",                                                      mime: mimeText },
+            // Multiple browsers seem to cheat a bit and race img.onLoad and setting responseEnd.  Microsoft https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/2379187
+            // { initiator: "img",            responsePart1: greenPng.substring(0, greenPng.length / 2), responsePart2: "0x" + greenPng.substring(greenPng.length / 2, greenPng.length),       mime: mimePng },
+            { initiator: "script",         responsePart1: '"', responsePart2: '";',                                                                                                         mime: mimeScript },
+            { initiator: "link",           responsePart1: ".unused{", responsePart2: "}",                                                                                                   mime: mimeCss },
+        ]
+        .forEach(function (template) {
+            testCases.push({
+                description: "'" + template.initiator + ": " + serverStepDelay + "ms delay before 'responseStart', another " + serverStepDelay + "ms delay before 'responseEnd'.",
+                test: function (test) {
+                    initiateFetch(
+                        test,
+                        template.initiator,
+                        getSyntheticUrl(serverStepDelay + "ms"                          // Wait, then echo back responsePart1
+                            + "&mime:" + encodeURIComponent(template.mime)
+                            + "&send:" + encodeURIComponent(template.responsePart1)
+                            + "&" + serverStepDelay + "ms"                              // Wait, then echo back responsePart2
+                            + "&send:" + encodeURIComponent(template.responsePart2)),
+
+                        function (initiator, entry) {
+                            // Per https://w3c.github.io/resource-timing/#performanceresourcetiming:
+                            // If no redirects (or equivalent) occur, this redirectStart/End must return zero.
+                            assert_equals(entry.redirectStart, 0, "When no redirect occurs, redirectStart must be 0.");
+                            assert_equals(entry.redirectEnd, 0, "When no redirect occurs, redirectEnd must be 0.");
+
+                            // Server creates a gap between 'requestStart' and 'responseStart'.
+                            assert_greater_than_equal(
+                                entry.responseStart,
+                                entry.requestStart + serverStepDelay,
+                                "'responseStart' must be " + serverStepDelay + "ms later than 'requestStart'.");
+
+                            // Server creates a gap between 'responseStart' and 'responseEnd'.
+                            assert_greater_than_equal(
+                                entry.responseEnd,
+                                entry.responseStart + serverStepDelay,
+                                "'responseEnd' must be " + serverStepDelay + "ms later than 'responseStart'.");
+
+                            test.done();
+                        });
+                    }
+                });
+            });
+
+        // Create redirectEnd/responseStart tests from the following array of templates.  In this test, the server delays before
+        // redirecting to a new synthetic response, then delays again before responding with 'response'.  The test looks for the
+        // expected pauses before redirectEnd and responseStart.
+        [
+            { initiator: "iframe",         response: serverStepDelay + "ms;redirect;" + (serverStepDelay * 2) + "ms;(done)",        mime: mimeHtml },
+            { initiator: "xmlhttprequest", response: serverStepDelay + "ms;redirect;" + (serverStepDelay * 2) + "ms;(done)",        mime: mimeText },
+            // Multiple browsers seem to cheat a bit and race img.onLoad and setting responseEnd.  Microsoft https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/2379187
+            // { initiator: "img",            response: greenPng,                                                                      mime: mimePng },
+            { initiator: "script",         response: '"";',                                                                         mime: mimeScript },
+            { initiator: "link",           response: ".unused{}",                                                                   mime: mimeCss },
+        ]
+        .forEach(function (template) {
+            testCases.push({
+                description: "'" + template.initiator + " (Redirected): " + serverStepDelay + "ms delay before 'redirectEnd', another " + serverStepDelay + "ms delay before 'responseStart'.",
+                test: function (test) {
+                    initiateFetch(
+                        test,
+                        template.initiator,
+                        getSyntheticUrl(serverStepDelay + "ms"      // Wait, then redirect to a second page that waits
+                            + "&redirect:"                          // before echoing back the response.
+                                + encodeURIComponent(
+                                    getSyntheticUrl(serverStepDelay + "ms"
+                                        + "&mime:" + encodeURIComponent(template.mime)
+                                        + "&send:" + encodeURIComponent(template.response)))),
+                        function (initiator, entry) {
+                            // Per https://w3c.github.io/resource-timing/#performanceresourcetiming:
+                            //      "[If redirected, startTime] MUST return the same value as redirectStart.
+                            assert_equals(entry.startTime, entry.redirectStart, "startTime must be equal to redirectStart.");
+
+                            // Server creates a gap between 'redirectStart' and 'redirectEnd'.
+                            assert_greater_than_equal(
+                                entry.redirectEnd,
+                                entry.redirectStart + serverStepDelay,
+                                "'redirectEnd' must be " + serverStepDelay + "ms later than 'redirectStart'.");
+
+                            // Server creates a gap between 'requestStart' and 'responseStart'.
+                            assert_greater_than_equal(
+                                entry.responseStart,
+                                entry.requestStart + serverStepDelay,
+                                "'responseStart' must be " + serverStepDelay + "ms later than 'requestStart'.");
+
+                            test.done();
+                        });
+                    }
+                });
+            });
+
+        // Ensure that responseStart only measures the time up to the first few
+        // bytes of the header response. This is tested by writing an HTTP 1.1
+        // status line, followed by a flush, then a pause before the end of the
+        // headers. The test makes sure that responseStart is not delayed by
+        // this pause.
+        [
+            { initiator: "iframe",         response: "(done)",    mime: mimeHtml },
+            { initiator: "xmlhttprequest", response: "(done)",    mime: mimeText },
+            { initiator: "script",         response: '"";',       mime: mimeScript },
+            { initiator: "link",           response: ".unused{}", mime: mimeCss },
+        ]
+        .forEach(function (template) {
+            testCases.push({
+                description: "'" + template.initiator + " " + serverStepDelay + "ms delay in headers does not affect responseStart'",
+                test: function (test) {
+                    initiateFetch(
+                        test,
+                        template.initiator,
+                        getSyntheticUrl("status:200"
+                                        + "&flush"
+                                        + "&" + serverStepDelay + "ms"
+                                        + "&mime:" + template.mime
+                                        + "&send:" + encodeURIComponent(template.response)),
+                        function (initiator, entry) {
+                            // Test that the delay between 'responseStart' and
+                            // 'responseEnd' includes the delay, which implies
+                            // that 'responseStart' was measured at the time of
+                            // status line receipt.
+                            assert_greater_than_equal(
+                                entry.responseEnd,
+                                entry.responseStart + serverStepDelay,
+                                "Delay after HTTP/1.1 status should not affect 'responseStart'.");
+
+                            test.done();
+                        });
+                    }
+                });
+            });
+
+        // Test that responseStart uses the timing of 1XX responses by
+        // synthesizing a delay between a 100 and 200 status, and verifying that
+        // this delay is included before responseEnd. If the delay is not
+        // included, this implies that the 200 status line was (incorrectly) used
+        // for responseStart timing, despite the 100 response arriving earlier.
+        //
+        // Source: "In the case where more than one response is available for a
+        // request, due to an Informational 1xx response, the reported
+        // responseStart value is that of the first response to the last
+        // request."
+        [
+            { initiator: "iframe",         response: "(done)",    mime: mimeHtml },
+            { initiator: "xmlhttprequest", response: "(done)",    mime: mimeText },
+            { initiator: "script",         response: '"";',       mime: mimeScript },
+            { initiator: "link",           response: ".unused{}", mime: mimeCss },
+        ]
+        .forEach(function (template) {
+            testCases.push({
+                description: "'" + template.initiator + " responseStart uses 1XX (first) response timings'",
+                test: function (test) {
+                    initiateFetch(
+                        test,
+                        template.initiator,
+                        getSyntheticUrl("status:100"
+                                        + "&flush"
+                                        + "&" + serverStepDelay + "ms"
+                                        + "&status:200"
+                                        + "&mime:" + template.mime
+                                        + "&send:" + encodeURIComponent(template.response)),
+                        function (initiator, entry) {
+                            assert_greater_than_equal(
+                                entry.responseEnd,
+                                entry.responseStart + serverStepDelay,
+                                "HTTP/1.1 1XX (first) response should determine 'responseStart' timing.");
+
+                            test.done();
+                        });
+                    }
+                });
+            });
+
+        // Function to run the next case in the queue.
+        var currentTestIndex = -1;
+        function runNextCase() {
+            var testCase = testCases[++currentTestIndex];
+            if (testCase !== undefined) {
+                async_test(testCase.test, testCase.description);
+            }
+        }
+
+        // When a test completes, run the next case in the queue.
+        add_result_callback(runNextCase);
+
+        // Start the first test.
+        runNextCase();
+
+        /** Iterates through all resource entries on the timeline, vetting all invariants. */
+        function assertInvariants(test, done) {
+            // Multiple browsers seem to cheat a bit and race img.onLoad and setting responseEnd.  Microsoft https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/2379187
+            // Yield for 100ms to workaround a suspected race where window.onload fires before
+            //     script visible side-effects from the wininet/urlmon thread have finished.
+            test.step_timeout(
+                test.step_func(
+                    function () {
+                        performance
+                            .getEntriesByType("resource")
+                            .forEach(
+                                function (entry, index, entries) {
+                                    assertResourceEntryInvariants(entry);
+                                });
+
+                        done();
+                    }),
+                    100);
+        }
+
+        /** Assets the invariants for a resource timeline entry. */
+        function assertResourceEntryInvariants(actual) {
+            // Example from http://w3c.github.io/resource-timing/#resources-included:
+            //     "If an HTML IFRAME element is added via markup without specifying a src attribute,
+            //      the user agent may load the about:blank document for the IFRAME. If at a later time
+            //      the src attribute is changed dynamically via script, the user agent may fetch the new
+            //      URL resource for the IFRAME. In this case, only the fetch of the new URL would be
+            //      included as a PerformanceResourceTiming object in the Performance Timeline."
+            assert_not_equals(
+                actual.name,
+                "about:blank",
+                "Fetch for 'about:blank' must not appear in timeline.");
+
+            assert_not_equals(actual.startTime, 0, "startTime");
+
+            // Per https://w3c.github.io/resource-timing/#performanceresourcetiming:
+            //      "[If redirected, startTime] MUST return the same value as redirectStart. Otherwise,
+            //      [startTime] MUST return the same value as fetchStart."
+            assert_in_array(actual.startTime, [actual.redirectStart, actual.fetchStart],
+                "startTime must be equal to redirectStart or fetchStart.");
+
+            // redirectStart <= redirectEnd <= fetchStart <= domainLookupStart <= domainLookupEnd <= connectStart
+            assert_less_than_equal(actual.redirectStart, actual.redirectEnd, "redirectStart <= redirectEnd");
+            assert_less_than_equal(actual.redirectEnd, actual.fetchStart, "redirectEnd <= fetchStart");
+            assert_less_than_equal(actual.fetchStart, actual.domainLookupStart, "fetchStart <= domainLookupStart");
+            assert_less_than_equal(actual.domainLookupStart, actual.domainLookupEnd, "domainLookupStart <= domainLookupEnd");
+            assert_less_than_equal(actual.domainLookupEnd, actual.connectStart, "domainLookupEnd <= connectStart");
+
+            // Per https://w3c.github.io/resource-timing/#performanceresourcetiming:
+            //      "This attribute is optional. User agents that don't have this attribute available MUST set it
+            //      as undefined.  [...]  If the secureConnectionStart attribute is available but HTTPS is not used,
+            //      this attribute MUST return zero."
+            assert_true(actual.secureConnectionStart == undefined ||
+                        actual.secureConnectionStart == 0 ||
+                        actual.secureConnectionStart >= actual.connectEnd, "secureConnectionStart time");
+
+            // connectStart <= connectEnd <= requestStart <= responseStart <= responseEnd
+            assert_less_than_equal(actual.connectStart, actual.connectEnd, "connectStart <= connectEnd");
+            assert_less_than_equal(actual.connectEnd, actual.requestStart, "connectEnd <= requestStart");
+            assert_less_than_equal(actual.requestStart, actual.responseStart, "requestStart <= responseStart");
+            assert_less_than_equal(actual.responseStart, actual.responseEnd, "responseStart <= responseEnd");
+        }
+
+        /** Helper function to resolve a relative URL */
+        function canonicalize(url) {
+            var div = document.createElement('div');
+            div.innerHTML = "<a></a>";
+            div.firstChild.href = url;
+            div.innerHTML = div.innerHTML;
+            return div.firstChild.href;
+        }
+
+        /** Generates a unique string, used by getSyntheticUrl() to avoid hitting the cache. */
+        function createUniqueQueryArgument() {
+            var result =
+                "ignored_"
+                    + Date.now()
+                    + "-"
+                    + ((Math.random() * 0xFFFFFFFF) >>> 0)
+                    + "-"
+                    + syntheticRequestCount;
+
+            return result;
+        }
+
+        /** Count of the calls to getSyntheticUrl().  Used by createUniqueQueryArgument() to generate unique strings. */
+        var syntheticRequestCount = 0;
+
+        /** Return a URL to a server that will synthesize an HTTP response using the given
+            commands. (See SyntheticResponse.aspx). */
+        function getSyntheticUrl(commands, allowCache) {
+            syntheticRequestCount++;
+
+            var url =
+                canonicalize("./SyntheticResponse.py")    // ASP.NET page that will synthesize the response.
+                    + "?" + commands;                       // Commands that will be used.
+
+            if (allowCache !== true) {                      // If caching is disallowed, append a unique argument
+                url += "&" + createUniqueQueryArgument();   // to the URL's query string.
+            }
+
+            return url;
+        }
+
+        /** Given an 'initiatorType' (e.g., "img") , it triggers the appropriate type of fetch for the specified
+            url and invokes 'onloadCallback' when the fetch completes.  If the fetch caused an entry to be created
+            on the resource timeline, the entry is passed to the callback. */
+        function initiateFetch(test, initiatorType, url, onloadCallback) {
+            assertInvariants(
+                test,
+                function () {
+                    log("--- Begin: " + url);
+
+                    switch (initiatorType) {
+                        case "script":
+                        case "img":
+                        case "iframe": {
+                            var element = document.createElement(initiatorType);
+                            document.body.appendChild(element);
+                            element.onload = createOnloadCallbackFn(test, element, url, onloadCallback);
+                            element.src = url;
+                            break;
+                        }
+                        case "link": {
+                            var element = document.createElement(initiatorType);
+                            element.rel = "stylesheet";
+                            document.body.appendChild(element);
+                            element.onload = createOnloadCallbackFn(test, element, url, onloadCallback);
+                            element.href = url;
+                            break;
+                        }
+                        case "xmlhttprequest": {
+                            var xhr = new XMLHttpRequest();
+                            xhr.open('GET', url, true);
+                            xhr.onreadystatechange = createOnloadCallbackFn(test, xhr, url, onloadCallback);
+                            xhr.send();
+                            break;
+                        }
+                        default:
+                            assert_unreached("Unsupported initiatorType '" + initiatorType + "'.");
+                            break;
+                    }});
+        }
+
+        /** Used by 'initiateFetch' to register a test step for the asynchronous callback, vet invariants,
+            find the matching resource timeline entry (if any), and pass it to the given 'onloadCallback'
+            when invoked. */
+        function createOnloadCallbackFn(test, initiator, url, onloadCallback) {
+            // Remember the number of entries on the timeline prior to initiating the fetch:
+            var beforeEntryCount = performance.getEntriesByType("resource").length;
+
+            return test.step_func(
+                function() {
+                    // If the fetch was initiated by XHR, we're subscribed to the 'onreadystatechange' event.
+                    // Ignore intermediate callbacks and wait for the XHR to complete.
+                    if (Object.getPrototypeOf(initiator) === XMLHttpRequest.prototype) {
+                        if (initiator.readyState != 4) {
+                            return;
+                        }
+                    }
+
+                    var entries = performance.getEntriesByType("resource");
+                    var candidateEntry = entries[entries.length - 1];
+
+                    switch (entries.length - beforeEntryCount)
+                    {
+                        case 0:
+                            candidateEntry = undefined;
+                            break;
+                        case 1:
+                            // Per https://w3c.github.io/resource-timing/#performanceresourcetiming:
+                            //     "This attribute MUST return the resolved URL of the requested resource. This attribute
+                            //      MUST NOT change even if the fetch redirected to a different URL."
+                            assert_equals(candidateEntry.name, url, "'name' did not match expected 'url'.");
+                            logResourceEntry(candidateEntry);
+                            break;
+                        default:
+                            assert_unreached("At most, 1 entry should be added to the performance timeline during a fetch.");
+                            break;
+                    }
+
+                    assertInvariants(
+                        test,
+                        function () {
+                            onloadCallback(initiator, candidateEntry);
+                        });
+                });
+        }
+
+        /** Log the given text to the document element with id='output' */
+        function log(text) {
+            var output = document.getElementById("output");
+            output.textContent += text + "\r\n";
+        }
+
+        add_completion_callback(function () {
+            var output = document.getElementById("output");
+            var button = document.createElement('button');
+            output.parentNode.insertBefore(button, output);
+            button.onclick = function () {
+                var showButton = output.style.display == 'none';
+                output.style.display = showButton ? null : 'none';
+                button.textContent = showButton ? 'Hide details' : 'Show details';
+            }
+            button.onclick();
+            var iframes = document.querySelectorAll('iframe');
+            for (var i = 0; i < iframes.length; i++)
+                iframes[i].parentNode.removeChild(iframes[i]);
+        });
+
+        /** pretty print a resource timeline entry. */
+        function logResourceEntry(entry) {
+            log("[" + entry.entryType + "] " + entry.name);
+
+            ["startTime", "redirectStart", "redirectEnd", "fetchStart", "domainLookupStart", "domainLookupEnd", "connectStart", "secureConnectionStart", "connectEnd", "requestStart", "responseStart", "responseEnd"]
+                .forEach(
+                    function (property, index, array) {
+                        var value = entry[property];
+                        log(property + ":\t" + value);
+                    });
+
+            log("\r\n");
+        }
+    };
diff --git a/test/fixtures/wpt/resource-timing/resource-timing-level1.sub.html b/test/fixtures/wpt/resource-timing/resource-timing-level1.sub.html
new file mode 100644
index 00000000000000..093d2542218fbe
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resource-timing-level1.sub.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <title>Resource-Timing Level 1</title>
+  <meta name="timeout" content="long">
+  <!-- To aid debugability, explicitly link the testharness's CSS to avoid demand
+       loading it while the test executes. -->
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+
+  <link rel="author" title="Microsoft" href="http://www.microsoft.com/">
+  <link rel="help" href="https://w3c.github.io/resource-timing/">
+</head>
+<body>
+  <div id="log"></div>
+  <pre id="output"></pre>
+  <script src="resource-timing-level1.js"></script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/resource_connection_reuse_mixed_content.html b/test/fixtures/wpt/resource-timing/resource_connection_reuse_mixed_content.html
new file mode 100644
index 00000000000000..51c04ee604c963
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resource_connection_reuse_mixed_content.html
@@ -0,0 +1,55 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing connection reuse</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/webperftestharness.js"></script>
+<script src="resources/webperftestharnessextension.js"></script>
+<script>
+setup({explicit_done: true});
+let iframe;
+let d;
+let body;
+
+// Explicitly test the namespace before we start testing.
+test_namespace('getEntriesByType');
+
+function setup_iframe() {
+    iframe = document.getElementById('frameContext');
+    d = iframe.contentWindow.document;
+    iframe.addEventListener('load', onload_test, false);
+}
+
+function onload_test() {
+    const entries = iframe.contentWindow.performance.getEntriesByType('resource');
+
+    // When a persistent connection is used, follow-on resources should be included as PerformanceResourceTiming objects.
+    test_equals(entries.length, 2, 'There should be 2 PerformanceEntries');
+
+    if (entries.length >= 2) {
+        // When a persistent connection is used, for the resource that reuses the socket, connectStart and connectEnd should have the same value as fetchStart.
+        const entry = entries[1];
+        test_equals(entry.fetchStart, entry.connectStart, 'connectStart and fetchStart should be the same');
+        test_equals(entry.fetchStart, entry.connectEnd, 'connectEnd and fetchStart should be the same');
+        // secureConnectionStart is the same as fetchStart since the subresource is fetched over https
+        test_equals(entry.fetchStart, entry.secureConnectionStart, 'secureConnectionStart and fetchStart should be the same');
+        test_equals(entry.fetchStart, entry.domainLookupStart, 'domainLookupStart and fetchStart should be the same')
+        test_equals(entry.fetchStart, entry.domainLookupEnd, 'domainLookupEnd and fetchStart should be the same')
+    }
+
+    done();
+}
+
+window.setup_iframe = setup_iframe;
+</script>
+</head>
+<body>
+<h1>Description</h1>
+<p>This test validates that connectStart and connectEnd are the same when a connection is reused (e.g. when a persistent connection is used).</p>
+<div id="log"></div>
+<iframe id="frameContext" src="resources/fake_responses_https.sub.html"></iframe>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/resource_connection_reuse_mixed_content_redirect.html b/test/fixtures/wpt/resource-timing/resource_connection_reuse_mixed_content_redirect.html
new file mode 100644
index 00000000000000..a46d14c9f159ad
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resource_connection_reuse_mixed_content_redirect.html
@@ -0,0 +1,55 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing connection reuse</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/webperftestharness.js"></script>
+<script src="resources/webperftestharnessextension.js"></script>
+<script>
+setup({explicit_done: true});
+let iframe;
+let d;
+let body;
+
+// Explicitly test the namespace before we start testing.
+test_namespace('getEntriesByType');
+
+function setup_iframe() {
+    iframe = document.getElementById('frameContext');
+    d = iframe.contentWindow.document;
+    iframe.addEventListener('load', onload_test, false);
+}
+
+function onload_test() {
+    const entries = iframe.contentWindow.performance.getEntriesByType('resource');
+
+    // When a persistent connection is used, follow-on resources should be included as PerformanceResourceTiming objects.
+    test_equals(entries.length, 2, 'There should be 2 PerformanceEntries');
+
+    if (entries.length >= 2) {
+        // When a persistent connection is used, for the resource that reuses the socket, connectStart and connectEnd should have the same value as fetchStart.
+        const entry = entries[1];
+        test_equals(entry.fetchStart, entry.connectStart, 'connectStart and fetchStart should be the same');
+        test_equals(entry.fetchStart, entry.connectEnd, 'connectEnd and fetchStart should be the same');
+        // secureConnectionStart is the same as fetchStart since the subresource is eventually redirected to https.
+        test_equals(entry.fetchStart, entry.secureConnectionStart, 'secureConnectionStart and fetchStart should be the same');
+        test_equals(entry.fetchStart, entry.domainLookupStart, 'domainLookupStart and fetchStart should be the same')
+        test_equals(entry.fetchStart, entry.domainLookupEnd, 'domainLookupEnd and fetchStart should be the same')
+    }
+
+    done();
+}
+
+window.setup_iframe = setup_iframe;
+</script>
+</head>
+<body>
+<h1>Description</h1>
+<p>This test validates that connectStart and connectEnd are the same when a connection is reused (e.g. when a persistent connection is used).</p>
+<div id="log"></div>
+<iframe id="frameContext" src="resources/fake_responses_https_redirect.sub.html"></iframe>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/resource_dedicated_worker.html b/test/fixtures/wpt/resource-timing/resource_dedicated_worker.html
new file mode 100644
index 00000000000000..6d27245ab9cc9a
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resource_dedicated_worker.html
@@ -0,0 +1,28 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing in dedicated workers</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="http://www.w3.org/TR/resource-timing/"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/webperftestharness.js"></script>
+<script src="resources/webperftestharnessextension.js"></script>
+<link rel="stylesheet" href="resources/resource_timing_test0.css" />
+<script>
+setup({explicit_done: true});
+const worker = new Worker("resources/worker_with_images.js");
+worker.onmessage = function(event) {
+  const context = new PerformanceContext(window.performance);
+  const entries = context.getEntriesByType('resource');
+  test_equals(entries.length, 6, "There should be six entries: 4 scripts, 1 stylesheet, and the worker itself");
+  done();
+}
+</script>
+</head>
+<body>
+<h1>Description</h1>
+<p>This test validates that resources requested by dedicated workers don't appear in the main document.</p>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/resource_nested_dedicated_worker.worker.js b/test/fixtures/wpt/resource-timing/resource_nested_dedicated_worker.worker.js
new file mode 100644
index 00000000000000..2c9f5f95428aca
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resource_nested_dedicated_worker.worker.js
@@ -0,0 +1,17 @@
+importScripts("/resources/testharness.js");
+
+async_test(function() {
+  const worker = new Worker('resources/worker_with_images.js');
+  worker.onmessage = this.step_func_done((event) => {
+    const childNumEntries = event.data;
+    assert_equals(2, childNumEntries,
+      "There should be two resource timing entries: 2 image XHRs");
+
+    const parentNumEntries = performance.getEntries().length;
+    assert_equals(2, parentNumEntries,
+      "There should be two resource timing entries: " +
+      "one is for importScripts() and the another is for a nested worker");
+    worker.terminate();
+  });
+}, "Resource timing for nested dedicated workers");
+done();
diff --git a/test/fixtures/wpt/resource-timing/resource_reparenting.html b/test/fixtures/wpt/resource-timing/resource_reparenting.html
new file mode 100644
index 00000000000000..7d4947fa7703d1
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resource_reparenting.html
@@ -0,0 +1,53 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing reparenting elements</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help" href="http://www.w3.org/TR/resource-timing/#dom-performanceresourcetiming-initiatortype"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/webperftestharness.js"></script>
+<script src="resources/webperftestharnessextension.js"></script>
+<script>
+let iframe;
+function setup_iframe() {
+    iframe = document.getElementById('frameContext');
+    const d = iframe.contentWindow.document;
+    const iframeBody = d.createElement('body');
+
+    const move_to_parent = d.createElement('img');
+    move_to_parent.src = 'blue.png?id=move_to_parent';
+    iframeBody.appendChild(move_to_parent);
+    iframeBody.removeChild(move_to_parent);
+
+    const parentBody = document.getElementsByTagName('body')[0];
+    parentBody.appendChild(move_to_parent);
+
+    const move_to_child = document.createElement('img');
+    move_to_child.src = 'blue.png?id=move_to_child';
+    parentBody.appendChild(move_to_child);
+    parentBody.removeChild(move_to_child);
+    iframeBody.appendChild(move_to_child);
+}
+function onload_test() {
+    const context = new PerformanceContext(iframe.contentWindow.performance);
+    const entries = context.getEntriesByType('resource');
+
+    const index = window.location.pathname.lastIndexOf('/');
+    const pathname = window.location.pathname.substring(0, index);
+    let expected_entries = {};
+    expected_entries[pathname + '/resources/blue.png?id=move_to_child'] = 'img';
+
+    test_resource_entries(entries, expected_entries);
+}
+window.setup_iframe = setup_iframe;
+</script>
+</head>
+<body>
+<h1>Description</h1>
+<p>This test validates that reparenting an element doesn't change the initiator document.</p>
+<div id="log"></div>
+<iframe id="frameContext" onload="onload_test();" src="resources/inject_resource_test.html"></iframe>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/resource_subframe_self_navigation.html b/test/fixtures/wpt/resource-timing/resource_subframe_self_navigation.html
new file mode 100644
index 00000000000000..5843f88307233e
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resource_subframe_self_navigation.html
@@ -0,0 +1,53 @@
+<!DOCTYPE html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<body>
+<script>
+function numberOfDownloads(url) {
+    let absoluteURL = new URL(url, location.href).href;
+    return performance.getEntriesByName(absoluteURL).length;
+}
+
+function waitForSubFrameLoad() {
+    return new Promise((resolve) => {
+        window.subFrameLoaded = () => {
+            window.subFrameLoaded = null;
+            resolve();
+        };
+    });
+}
+
+function runTest(type) {
+    performance.clearResourceTimings();
+    let elem = document.createElement(type);
+    if (type === 'object')
+        elem.data = 'resources/self_navigation.html?' + type;
+    else
+        elem.src = 'resources/self_navigation.html?' + type;
+    document.body.appendChild(elem);
+    return waitForSubFrameLoad().then(() => {
+        let resources = performance.getEntriesByType('resource');
+        assert_equals(numberOfDownloads('resources/self_navigation.html?' + type), 1);
+        assert_equals(numberOfDownloads('resources/notify_parent.html?redirected'), 0);
+        document.body.removeChild(elem);
+    });
+}
+
+promise_test(
+    () => runTest('iframe'),
+    "Subsequent <iframe> navigations don't appear in the resource-timing buffer.");
+
+promise_test(
+    () => runTest('frame'),
+    "Subsequent <frame> navigations don't appear in the resource-timing buffer.");
+
+promise_test(
+    () => runTest('embed'),
+    "Subsequent <embed> navigations don't appear in the resource-timing buffer.");
+
+promise_test(
+    () => runTest('object'),
+    "Subsequent <object> navigations don't appear in the resource-timing buffer.");
+
+</script>
+</body>
diff --git a/test/fixtures/wpt/resource-timing/resource_timing.worker.js b/test/fixtures/wpt/resource-timing/resource_timing.worker.js
new file mode 100644
index 00000000000000..dafd2e9af602ed
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resource_timing.worker.js
@@ -0,0 +1,64 @@
+importScripts("/resources/testharness.js");
+
+function check(initiatorType, protocol) {
+  let entries = performance.getEntries();
+  assert_equals(entries.length, 1);
+
+  assert_true(entries[0] instanceof PerformanceEntry);
+  assert_equals(entries[0].entryType, "resource");
+  assert_true(entries[0].startTime > 0);
+  assert_true(entries[0].duration > 0);
+
+  assert_true(entries[0] instanceof PerformanceResourceTiming);
+  assert_equals(entries[0].initiatorType, initiatorType);
+  assert_equals(entries[0].nextHopProtocol, protocol);
+}
+
+async_test(t => {
+  performance.clearResourceTimings();
+
+  // Fetch
+  fetch("resources/empty.js")
+  .then(r => r.blob())
+  .then(blob => {
+    check("fetch", "http/1.1");
+  })
+
+  // XMLHttpRequest
+  .then(() => {
+    return new Promise(resolve => {
+      performance.clearResourceTimings();
+      let xhr = new XMLHttpRequest();
+      xhr.onload = () => {
+        check("xmlhttprequest", "http/1.1");
+        resolve();
+      };
+      xhr.open("GET", "resources/empty.js");
+      xhr.send();
+    });
+  })
+
+  // Sync XMLHttpREquest
+  .then(() => {
+    performance.clearResourceTimings();
+    let xhr = new XMLHttpRequest();
+    xhr.open("GET", "resources/empty.js", false);
+    xhr.send();
+
+    check("xmlhttprequest", "http/1.1");
+  })
+
+  // ImportScripts
+  .then(() => {
+    performance.clearResourceTimings();
+    importScripts(["resources/empty.js"]);
+    check("other", "http/1.1");
+  })
+
+  // All done.
+  .then(() => {
+    t.done();
+  });
+}, "Performance Resource Entries in workers");
+
+done();
diff --git a/test/fixtures/wpt/resource-timing/resource_timing_content_length.html b/test/fixtures/wpt/resource-timing/resource_timing_content_length.html
new file mode 100644
index 00000000000000..32bd8a97e07341
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resource_timing_content_length.html
@@ -0,0 +1,35 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>This test validates the value of encodedBodySize in certain situations.</title>
+<link rel="help" href="http://www.w3.org/TR/resource-timing/#performanceresourcetiming"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<script>
+    function test_resource_timing_for_content_length({actualContentLength, lengthHeader}, title) {
+        promise_test(async t => {
+            const content = new Array(actualContentLength).fill('x').join('')
+            const url = `resources/resource-timing-content-length.py?content=${content}&length=${lengthHeader}`
+            fetch(url)
+            const entry = await new Promise(resolve => new PerformanceObserver((entryList, observer) => {
+                observer.disconnect()
+                resolve(entryList.getEntries()[0])
+            }).observe({entryTypes: ['resource']}))
+
+            const expectedContentLength = Number.isInteger(lengthHeader) ? Math.min(actualContentLength, lengthHeader) : actualContentLength
+            assert_equals(entry.encodedBodySize, expectedContentLength)
+        }, title);
+    }
+
+    test_resource_timing_for_content_length({actualContentLength: 3, lengthHeader: 'auto'},
+        "encodedBodySize should be equal to the actual byte size of the content")
+    test_resource_timing_for_content_length({actualContentLength: 13, lengthHeader: 'none'},
+        "encodedBodySize should be equal to the actual byte size of the content when no header present")
+    test_resource_timing_for_content_length({actualContentLength: 7, lengthHeader: 3},
+        "encodedBodySize should be equal to the actual byte size of the content when header value is lower than actual content")
+    test_resource_timing_for_content_length({actualContentLength: 8, lengthHeader: 40},
+        "encodedBodySize should be equal to the actual byte size of the content when header value is higher than actual content")
+</script>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/resources/200.https.asis b/test/fixtures/wpt/resource-timing/resources/200.https.asis
new file mode 100644
index 00000000000000..5b7c25f4ca03a2
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/200.https.asis
@@ -0,0 +1,5 @@
+HTTP/1.0 200 OK
+Content-Length: 0
+Timing-Allow-Origin: *
+
+
diff --git a/test/fixtures/wpt/resource-timing/resources/200_empty.asis b/test/fixtures/wpt/resource-timing/resources/200_empty.asis
new file mode 100644
index 00000000000000..b5d10bda324528
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/200_empty.asis
@@ -0,0 +1,3 @@
+HTTP/1.0 200 OK
+Content-Length: 0
+
diff --git a/test/fixtures/wpt/resource-timing/resources/204_empty.asis b/test/fixtures/wpt/resource-timing/resources/204_empty.asis
new file mode 100644
index 00000000000000..3d9151326b3544
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/204_empty.asis
@@ -0,0 +1,3 @@
+HTTP/1.0 204 OK
+Content-Length: 0
+
diff --git a/test/fixtures/wpt/resource-timing/resources/205_empty.asis b/test/fixtures/wpt/resource-timing/resources/205_empty.asis
new file mode 100644
index 00000000000000..2c06998c1eb19e
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/205_empty.asis
@@ -0,0 +1,3 @@
+HTTP/1.0 205 OK
+Content-Length: 0
+
diff --git a/test/fixtures/wpt/resource-timing/resources/blank-with-tao.html b/test/fixtures/wpt/resource-timing/resources/blank-with-tao.html
new file mode 100644
index 00000000000000..b8a1947b77e25a
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/blank-with-tao.html
@@ -0,0 +1,10 @@
+<!DOCTYPE HTML>
+<html>
+    <head>
+        <meta content="text/html; charset=utf-8" http-equiv="Content-Type" />
+        <title>Green Test Page</title>
+    </head>
+    <body style="background-color:#00FF00;">
+        <h1>Placeholder</h1>
+    </body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/resources/blank-with-tao.html.headers b/test/fixtures/wpt/resource-timing/resources/blank-with-tao.html.headers
new file mode 100644
index 00000000000000..7296361df3d1c5
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/blank-with-tao.html.headers
@@ -0,0 +1 @@
+Timing-Allow-Origin: *
diff --git a/test/fixtures/wpt/resource-timing/resources/blue-with-tao.png b/test/fixtures/wpt/resource-timing/resources/blue-with-tao.png
new file mode 100644
index 0000000000000000000000000000000000000000..820f8cace2143bfc45c0c301e84b6c29b8630068
GIT binary patch
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zcmeAS@N?(olHy`uVBq!ia0vp^2_VeD3?#3*wSy!Wi-X*q7}lMWc?smOq&xaLGB9lH
z=l+w(3gjy!dj$D1FjT2AFf_C<F#G}vHN0S8C^cYUc$L7wU^Rn*LA+qju0R_G24;o;
zpAc6DhW|h{qhK@yMrH^cH_nOz`dp&KHKHUqKdq!Zu_%=xATcwqM9<GPM4`-B&)96`
z^GB*cH4dIGjv*P&Z!a{0g6i;spTY4DI9dY|4>T|`v++n6B;aK<+8d}OFfd9ReoF^w
N_jL7hS?83{1OVd{KuZ7s

literal 0
HcmV?d00001

diff --git a/test/fixtures/wpt/resource-timing/resources/blue-with-tao.png.headers b/test/fixtures/wpt/resource-timing/resources/blue-with-tao.png.headers
new file mode 100644
index 00000000000000..7296361df3d1c5
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/blue-with-tao.png.headers
@@ -0,0 +1 @@
+Timing-Allow-Origin: *
diff --git a/test/fixtures/wpt/resource-timing/resources/blue.png b/test/fixtures/wpt/resource-timing/resources/blue.png
new file mode 100644
index 0000000000000000000000000000000000000000..820f8cace2143bfc45c0c301e84b6c29b8630068
GIT binary patch
literal 1010
zcmeAS@N?(olHy`uVBq!ia0vp^2_VeD3?#3*wSy!Wi-X*q7}lMWc?smOq&xaLGB9lH
z=l+w(3gjy!dj$D1FjT2AFf_C<F#G}vHN0S8C^cYUc$L7wU^Rn*LA+qju0R_G24;o;
zpAc6DhW|h{qhK@yMrH^cH_nOz`dp&KHKHUqKdq!Zu_%=xATcwqM9<GPM4`-B&)96`
z^GB*cH4dIGjv*P&Z!a{0g6i;spTY4DI9dY|4>T|`v++n6B;aK<+8d}OFfd9ReoF^w
N_jL7hS?83{1OVd{KuZ7s

literal 0
HcmV?d00001

diff --git a/test/fixtures/wpt/resource-timing/resources/buffer-full-utilities.js b/test/fixtures/wpt/resource-timing/resources/buffer-full-utilities.js
new file mode 100644
index 00000000000000..6cb1753b2e9fb8
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/buffer-full-utilities.js
@@ -0,0 +1,75 @@
+// This script relies on resources/resource-loaders.js. Include it before in order for the below
+// methods to work properly.
+
+// The resources used to trigger new entries.
+const scriptResources = [
+    'resources/empty.js',
+    'resources/empty_script.js',
+    'resources/empty.js?id'
+];
+
+const waitForNextTask = () => {
+    return new Promise(resolve => {
+        step_timeout(resolve, 0);
+    });
+};
+
+const clearBufferAndSetSize = size => {
+  performance.clearResourceTimings();
+  performance.setResourceTimingBufferSize(size);
+}
+
+const forceBufferFullEvent = async () => {
+  clearBufferAndSetSize(1);
+  return new Promise(async resolve => {
+    performance.addEventListener('resourcetimingbufferfull', resolve);
+    // Load 2 resources to ensure onresourcetimingbufferfull is fired.
+    // Load them in order in order to get the entries in that order!
+    await load.script(scriptResources[0]);
+    await load.script(scriptResources[1]);
+  });
+};
+
+const fillUpTheBufferWithSingleResource = async (src = scriptResources[0]) => {
+  clearBufferAndSetSize(1);
+  await load.script(src);
+};
+
+const fillUpTheBufferWithTwoResources = async () => {
+    clearBufferAndSetSize(2);
+    // Load them in order in order to get the entries in that order!
+    await load.script(scriptResources[0]);
+    await load.script(scriptResources[1]);
+};
+
+const addAssertUnreachedBufferFull = t => {
+  performance.addEventListener('resourcetimingbufferfull', t.step_func(() => {
+    assert_unreached("resourcetimingbufferfull should not fire")
+  }));
+};
+
+const checkEntries = numEntries => {
+  const entries = performance.getEntriesByType('resource');
+  assert_equals(entries.length, numEntries,
+      'Number of entries does not match the expected value.');
+  assert_true(entries[0].name.includes(scriptResources[0]),
+      scriptResources[0] + " is in the entries buffer");
+  if (entries.length > 1) {
+    assert_true(entries[1].name.includes(scriptResources[1]),
+        scriptResources[1] + " is in the entries buffer");
+  }
+  if (entries.length > 2) {
+    assert_true(entries[2].name.includes(scriptResources[2]),
+        scriptResources[2] + " is in the entries buffer");
+  }
+}
+
+const bufferFullFirePromise = new Promise(resolve => {
+  performance.addEventListener('resourcetimingbufferfull', async () => {
+    // Wait for the next task just to ensure that all bufferfull events have fired, and to ensure
+    // that the secondary buffer is copied (as this is an event, there may be microtask checkpoints
+    // right after running an event handler).
+    await waitForNextTask();
+    resolve();
+  });
+});
diff --git a/test/fixtures/wpt/resource-timing/resources/close.html b/test/fixtures/wpt/resource-timing/resources/close.html
new file mode 100644
index 00000000000000..02c275f37b66e8
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/close.html
@@ -0,0 +1 @@
+<script>window.close()</script>
\ No newline at end of file
diff --git a/test/fixtures/wpt/resource-timing/resources/connection-reuse-test.js b/test/fixtures/wpt/resource-timing/resources/connection-reuse-test.js
new file mode 100644
index 00000000000000..453fbd34051067
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/connection-reuse-test.js
@@ -0,0 +1,63 @@
+// This script is loaded in HTTP and HTTPS contexts to validate
+// PerformanceResourceTiming entries' attributes when reusing connections.
+//
+// Note: to ensure that we reuse the connection to fetch multiple resources, we
+// use the same XMLHttpRequest object throughout an individual test. Although
+// it doesn't seem to be specified, each browser tested by WPT will reuse the
+// underlying TCP connection with this approach. Pre-establishing the XHR's
+// connection helps us to test connection reuse also in browsers that may key
+// their connections on the related request's credentials mode.
+
+const connection_reuse_test = (path, follow_on_assertions, test_label) => {
+  const {on_200, on_304} = follow_on_assertions;
+
+  // Make the first request before calling 'attribute_test' so that only the
+  // second request's PerformanceResourceTiming entry will be interrogated. We
+  // don't check the first request's PerformanceResourceTiming entry because
+  // that's not what this test is trying to validate.
+  const client = new XMLHttpRequest();
+  const identifier = Math.random();
+  path = `${path}?tag=${identifier}`;
+  client.open("GET", path, false);
+  client.send();
+
+  attribute_test(
+    async () => {
+      client.open("GET", path + "&same_resource=false", false);
+      client.send();
+
+      // We expect to get a 200 Ok response because we've requested a different
+      // resource than previous requests.
+      if (client.status != 200) {
+        throw new Error(`Got something other than a 200 response. ` +
+                        `client.status: ${client.status}`);
+      }
+    }, path, entry => {
+      invariants.assert_connection_reused(entry);
+      on_200(entry);
+    },
+    `PerformanceResrouceTiming entries need to conform to the spec when a ` +
+    `distinct resource is fetched over a persistent connection ` +
+    `(${test_label})`);
+
+  attribute_test(
+    async () => {
+      client.open("GET", path, false);
+      client.setRequestHeader("If-None-Match", identifier);
+      client.send();
+
+      // We expect to get a 304 Not Modified response because we've used a
+      // matching 'identifier' for the If-None-Match header.
+      if (client.status != 304) {
+        throw new Error(`Got something other than a 304 response. ` +
+                        `client.status: ${client.status}, response: ` +
+                        `'${client.responseText}'`);
+      }
+    }, path, entry => {
+      invariants.assert_connection_reused(entry);
+      on_304(entry);
+    },
+    `PerformanceResrouceTiming entries need to conform to the spec when the ` +
+    `resource is cache-revalidated over a persistent connection ` +
+    `(${test_label})`);
+}
diff --git a/test/fixtures/wpt/resource-timing/resources/csp-default-none.html b/test/fixtures/wpt/resource-timing/resources/csp-default-none.html
new file mode 100644
index 00000000000000..1f59d8c2250f7f
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/csp-default-none.html
@@ -0,0 +1,3 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>empty page</title>
diff --git a/test/fixtures/wpt/resource-timing/resources/csp-default-none.html.headers b/test/fixtures/wpt/resource-timing/resources/csp-default-none.html.headers
new file mode 100644
index 00000000000000..d66f886dd23d44
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/csp-default-none.html.headers
@@ -0,0 +1,2 @@
+Content-Security-Policy: default-src 'none'
+
diff --git a/test/fixtures/wpt/resource-timing/resources/document-domain-no-impact.html b/test/fixtures/wpt/resource-timing/resources/document-domain-no-impact.html
new file mode 100644
index 00000000000000..64cdd8a8701eb4
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/document-domain-no-impact.html
@@ -0,0 +1,28 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+<meta charset="utf-8">
+<script src="/resources/testharness.js"></script>
+<script src="resource-loaders.js"></script>
+<script src="entry-invariants.js"></script>
+<body>
+<script>
+const path = location.origin +
+             "/resource-timing/resources/iframe-setdomain.sub.html";
+attribute_test_with_validator(load.iframe, path,
+  el => {
+    try {
+      el.contentWindow.document;
+      throw new Error("iframe document.domain was not set");
+    } catch(error) {
+      if (error.name != "SecurityError") {
+        throw(error);
+      }
+    }
+  },
+  invariants.assert_tao_pass_no_redirect_http,
+  "test that document.domain being set doesn't have an impact on the " +
+  "resource timing entry."
+);
+</script>
+
diff --git a/test/fixtures/wpt/resource-timing/resources/document-navigated.html b/test/fixtures/wpt/resource-timing/resources/document-navigated.html
new file mode 100644
index 00000000000000..bedae770824a3c
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/document-navigated.html
@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+</head>
+<body>
+  Navigated document!
+<script>
+  top.postMessage("navigated", "*");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/resources/document-refreshed.html b/test/fixtures/wpt/resource-timing/resources/document-refreshed.html
new file mode 100644
index 00000000000000..568f7f27c7d950
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/document-refreshed.html
@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+</head>
+<body>
+  Refreshed document!
+<script>
+  top.postMessage("refreshed", "*");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/resources/document-that-navigates.html b/test/fixtures/wpt/resource-timing/resources/document-that-navigates.html
new file mode 100644
index 00000000000000..a59e9f3ab2b783
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/document-that-navigates.html
@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+</head>
+<body>
+<script>
+  location.href="document-navigated.html";
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/resources/document-that-refreshes.html b/test/fixtures/wpt/resource-timing/resources/document-that-refreshes.html
new file mode 100644
index 00000000000000..659513a642f382
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/document-that-refreshes.html
@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<meta http-equiv="refresh" content="0;document-refreshed.html">
+</head>
+<body>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/resources/download.asis b/test/fixtures/wpt/resource-timing/resources/download.asis
new file mode 100644
index 00000000000000..167386d7a52d7c
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/download.asis
@@ -0,0 +1,6 @@
+HTTP/1.0 200 OK
+Content-Type: application/octet-stream
+
+12312313
+
+
diff --git a/test/fixtures/wpt/resource-timing/resources/embed-navigate-back.html b/test/fixtures/wpt/resource-timing/resources/embed-navigate-back.html
new file mode 100644
index 00000000000000..c9c7340f5307da
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/embed-navigate-back.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing embed navigate - back button navigation</title>
+</head>
+<body onunload="/*disable bfcache*/">
+<script src="/common/get-host-info.sub.js"></script>
+<script src="nested-contexts.js"></script>
+<script>
+  setup_back_navigation("embed-navigate-back.html");
+</script>
+<embed id="target" type="text/html">
+<script>
+  target.src = pre_navigate_url;
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/resources/embed-navigate.html b/test/fixtures/wpt/resource-timing/resources/embed-navigate.html
new file mode 100644
index 00000000000000..24c9d3c462730f
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/embed-navigate.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing embed navigate</title>
+</head>
+<body>
+<script src="/common/get-host-info.sub.js"></script>
+<script src="nested-contexts.js"></script>
+<script>
+  setup_navigate_test();
+</script>
+<embed id="target" type="text/html">
+<script>
+  target.src = pre_navigate_url;
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/resources/embed-refresh.html b/test/fixtures/wpt/resource-timing/resources/embed-refresh.html
new file mode 100644
index 00000000000000..bd4b5a14de9779
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/embed-refresh.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing embed refresh</title>
+</head>
+<body>
+<script src="/common/get-host-info.sub.js"></script>
+<script src="nested-contexts.js"></script>
+<script>
+  setup_refresh_test();
+</script>
+<embed id="target" type="text/html">
+<script>
+  target.src = pre_refresh_url;
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/resources/empty.js b/test/fixtures/wpt/resource-timing/resources/empty.js
new file mode 100644
index 00000000000000..3b44754e301ded
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/empty.js
@@ -0,0 +1 @@
+/* Nothing here */
diff --git a/test/fixtures/wpt/resource-timing/resources/empty_script.js b/test/fixtures/wpt/resource-timing/resources/empty_script.js
new file mode 100644
index 00000000000000..e69de29bb2d1d6
diff --git a/test/fixtures/wpt/resource-timing/resources/empty_style.css b/test/fixtures/wpt/resource-timing/resources/empty_style.css
new file mode 100644
index 00000000000000..eb90b432e8421f
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/empty_style.css
@@ -0,0 +1 @@
+/*Nothing here*/
diff --git a/test/fixtures/wpt/resource-timing/resources/entry-invariants.js b/test/fixtures/wpt/resource-timing/resources/entry-invariants.js
new file mode 100644
index 00000000000000..4bef9496103ca6
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/entry-invariants.js
@@ -0,0 +1,507 @@
+// Asserts that the given attributes are present in 'entry' and hold equal
+// values.
+const assert_all_equal_ = (entry, attributes) => {
+  let first = attributes[0];
+  attributes.slice(1).forEach(other => {
+    assert_equals(entry[first], entry[other],
+      `${first} should be equal to ${other}`);
+  });
+}
+
+// Asserts that the given attributes are present in 'entry' and hold values
+// that are sorted in the same order as given in 'attributes'.
+const assert_ordered_ = (entry, attributes) => {
+  let before = attributes[0];
+  attributes.slice(1).forEach(after => {
+    assert_greater_than_equal(entry[after], entry[before],
+      `${after} should be greater than ${before}`);
+    before = after;
+  });
+}
+
+// Asserts that the given attributes are present in 'entry' and hold a value of
+// 0.
+const assert_zeroed_ = (entry, attributes) => {
+  attributes.forEach(attribute => {
+    assert_equals(entry[attribute], 0, `${attribute} should be 0`);
+  });
+}
+
+// Asserts that the given attributes are present in 'entry' and hold a value of
+// 0 or more.
+const assert_not_negative_ = (entry, attributes) => {
+  attributes.forEach(attribute => {
+    assert_greater_than_equal(entry[attribute], 0,
+      `${attribute} should be greater than or equal to 0`);
+  });
+}
+
+// Asserts that the given attributes are present in 'entry' and hold a value
+// greater than 0.
+const assert_positive_ = (entry, attributes) => {
+  attributes.forEach(attribute => {
+    assert_greater_than(entry[attribute], 0,
+      `${attribute} should be greater than 0`);
+  });
+}
+
+const invariants = {
+  // Asserts that attributes of the given PerformanceResourceTiming entry match
+  // what the spec dictates for any resource fetched over HTTP without
+  // redirects but passing the Timing-Allow-Origin checks.
+  assert_tao_pass_no_redirect_http: entry => {
+    assert_ordered_(entry, [
+      "fetchStart",
+      "domainLookupStart",
+      "domainLookupEnd",
+      "connectStart",
+      "connectEnd",
+      "requestStart",
+      "responseStart",
+      "responseEnd",
+    ]);
+
+    assert_zeroed_(entry, [
+      "workerStart",
+      "secureConnectionStart",
+      "redirectStart",
+      "redirectEnd",
+    ]);
+
+    assert_not_negative_(entry, [
+      "duration",
+    ]);
+
+    assert_positive_(entry, [
+      "fetchStart",
+      "transferSize",
+      "encodedBodySize",
+      "decodedBodySize",
+    ]);
+  },
+
+  // Like assert_tao_pass_no_redirect_http but for empty response bodies.
+  assert_tao_pass_no_redirect_http_empty: entry => {
+    assert_ordered_(entry, [
+      "fetchStart",
+      "domainLookupStart",
+      "domainLookupEnd",
+      "connectStart",
+      "connectEnd",
+      "requestStart",
+      "responseStart",
+      "responseEnd",
+    ]);
+
+    assert_zeroed_(entry, [
+      "workerStart",
+      "secureConnectionStart",
+      "redirectStart",
+      "redirectEnd",
+      "encodedBodySize",
+      "decodedBodySize",
+    ]);
+
+    assert_not_negative_(entry, [
+      "duration",
+    ]);
+
+    assert_positive_(entry, [
+      "fetchStart",
+      "transferSize",
+    ]);
+  },
+
+  // Like assert_tao_pass_no_redirect_http but for resources fetched over HTTPS
+  assert_tao_pass_no_redirect_https: entry => {
+    assert_ordered_(entry, [
+      "fetchStart",
+      "domainLookupStart",
+      "domainLookupEnd",
+      "secureConnectionStart",
+      "connectStart",
+      "connectEnd",
+      "requestStart",
+      "responseStart",
+      "responseEnd",
+    ]);
+
+    assert_zeroed_(entry, [
+      "workerStart",
+      "redirectStart",
+      "redirectEnd",
+    ]);
+
+    assert_not_negative_(entry, [
+      "duration",
+    ]);
+
+    assert_positive_(entry, [
+      "fetchStart",
+      "transferSize",
+      "encodedBodySize",
+      "decodedBodySize",
+    ]);
+  },
+
+  // Like assert_tao_pass_no_redirect_https but for resources that did encounter
+  // at least one HTTP redirect.
+  assert_tao_pass_with_redirect_https: entry => {
+    assert_ordered_(entry, [
+      "fetchStart",
+      "redirectStart",
+      "redirectEnd",
+      "domainLookupStart",
+      "domainLookupEnd",
+      "secureConnectionStart",
+      "connectStart",
+      "connectEnd",
+      "requestStart",
+      "responseStart",
+      "responseEnd",
+    ]);
+
+    assert_zeroed_(entry, [
+      "workerStart",
+    ]);
+
+    assert_not_negative_(entry, [
+      "duration",
+    ]);
+
+    assert_positive_(entry, [
+      "fetchStart",
+      "transferSize",
+      "encodedBodySize",
+      "decodedBodySize",
+    ]);
+  },
+
+  // Like assert_tao_pass_no_redirect_http but, since the resource's bytes
+  // won't be retransmitted, the encoded and decoded sizes must be zero.
+  assert_tao_pass_304_not_modified_http: entry => {
+    assert_ordered_(entry, [
+      "fetchStart",
+      "domainLookupStart",
+      "domainLookupEnd",
+      "connectStart",
+      "connectEnd",
+      "requestStart",
+      "responseStart",
+      "responseEnd",
+    ]);
+
+    assert_zeroed_(entry, [
+      "workerStart",
+      "secureConnectionStart",
+      "redirectStart",
+      "redirectEnd",
+      "encodedBodySize",
+      "decodedBodySize",
+    ]);
+
+    assert_not_negative_(entry, [
+      "duration",
+    ]);
+
+    assert_positive_(entry, [
+      "fetchStart",
+      "transferSize",
+    ]);
+  },
+
+  // Like assert_tao_pass_304_not_modified_http but for resources fetched over
+  // HTTPS.
+  assert_tao_pass_304_not_modified_https: entry => {
+    assert_ordered_(entry, [
+      "fetchStart",
+      "domainLookupStart",
+      "domainLookupEnd",
+      "secureConnectionStart",
+      "connectStart",
+      "connectEnd",
+      "requestStart",
+      "responseStart",
+      "responseEnd",
+    ]);
+
+    assert_zeroed_(entry, [
+      "workerStart",
+      "redirectStart",
+      "redirectEnd",
+      "encodedBodySize",
+      "decodedBodySize",
+    ]);
+
+    assert_not_negative_(entry, [
+      "duration",
+    ]);
+
+    assert_positive_(entry, [
+      "fetchStart",
+      "transferSize",
+    ]);
+  },
+
+  // Asserts that attributes of the given PerformanceResourceTiming entry match
+  // what the spec dictates for any resource subsequently fetched over a
+  // persistent connection. When this happens, we expect that certain
+  // attributes describing transport layer behaviour will be equal.
+  assert_connection_reused: entry => {
+    assert_all_equal_(entry, [
+      "fetchStart",
+      "connectStart",
+      "connectEnd",
+      "domainLookupStart",
+      "domainLookupEnd",
+    ]);
+  },
+
+  // Asserts that attributes of the given PerformanceResourceTiming entry match
+  // what the spec dictates for any resource fetched over HTTP through an HTTP
+  // redirect.
+  assert_same_origin_redirected_resource: entry => {
+    assert_positive_(entry, [
+      "redirectStart",
+    ]);
+
+    assert_equals(entry.redirectStart, entry.startTime,
+      "redirectStart should be equal to startTime");
+
+    assert_ordered_(entry, [
+      "redirectStart",
+      "redirectEnd",
+      "fetchStart",
+      "domainLookupStart",
+      "domainLookupEnd",
+      "connectStart",
+    ]);
+  },
+
+  // Asserts that attributes of the given PerformanceResourceTiming entry match
+  // what the spec dictates for any resource fetched over HTTPS through a
+  // cross-origin redirect.
+  // (e.g. GET http://remote.com/foo => 302 Location: https://remote.com/foo)
+  assert_cross_origin_redirected_resource: entry => {
+    assert_zeroed_(entry, [
+      "redirectStart",
+      "redirectEnd",
+      "domainLookupStart",
+      "domainLookupEnd",
+      "connectStart",
+      "connectEnd",
+      "secureConnectionStart",
+      "requestStart",
+      "responseStart",
+    ]);
+
+    assert_positive_(entry, [
+      "fetchStart",
+      "responseEnd",
+    ]);
+
+    assert_ordered_(entry, [
+      "fetchStart",
+      "responseEnd",
+    ]);
+  },
+
+  // Asserts that attributes of the given PerformanceResourceTiming entry match
+  // what the spec dictates when
+  // 1. An HTTP request is made for a same-origin resource.
+  // 2. The response to 1 is an HTTP redirect (like a 302).
+  // 3. The location from 2 is a cross-origin HTTPS URL.
+  // 4. The response to fetching the URL from 3 does not set a matching TAO header.
+  assert_http_to_cross_origin_redirected_resource: entry => {
+    assert_zeroed_(entry, [
+      "redirectStart",
+      "redirectEnd",
+      "domainLookupStart",
+      "domainLookupEnd",
+      "connectStart",
+      "connectEnd",
+      "secureConnectionStart",
+      "requestStart",
+      "responseStart",
+    ]);
+
+    assert_positive_(entry, [
+      "fetchStart",
+      "responseEnd",
+    ]);
+
+    assert_ordered_(entry, [
+      "fetchStart",
+      "responseEnd",
+    ]);
+  },
+
+  // Asserts that attributes of the given PerformanceResourceTiming entry match
+  // what the spec dictates when
+  // 1. An HTTPS request is made for a same-origin resource.
+  // 2. The response to 1 is an HTTP redirect (like a 302).
+  // 3. The location from 2 is a cross-origin HTTPS URL.
+  // 4. The response to fetching the URL from 3 sets a matching TAO header.
+  assert_tao_enabled_cross_origin_redirected_resource: entry => {
+    assert_positive_(entry, [
+      "redirectStart",
+    ]);
+    assert_ordered_(entry, [
+      "redirectStart",
+      "redirectEnd",
+      "fetchStart",
+      "domainLookupStart",
+      "domainLookupEnd",
+      "connectStart",
+      "secureConnectionStart",
+      "connectEnd",
+      "requestStart",
+      "responseStart",
+      "responseEnd",
+    ]);
+  },
+
+  // Asserts that attributes of the given PerformanceResourceTiming entry match
+  // what the spec dictates when
+  // 1. An HTTP request is made for a same-origin resource
+  // 2. The response to 1 is an HTTP redirect (like a 302).
+  // 3. The location from 2 is a cross-origin HTTPS URL.
+  // 4. The response to fetching the URL from 3 sets a matching TAO header.
+  assert_http_to_tao_enabled_cross_origin_https_redirected_resource: entry => {
+    assert_zeroed_(entry, [
+      // Note that, according to the spec, the secureConnectionStart attribute
+      // should describe the connection for the first resource request when
+      // there are redirects. Since the initial request is over HTTP,
+      // secureConnectionStart must be 0.
+      "secureConnectionStart",
+    ]);
+    assert_positive_(entry, [
+      "redirectStart",
+    ]);
+    assert_ordered_(entry, [
+      "redirectStart",
+      "redirectEnd",
+      "fetchStart",
+      "domainLookupStart",
+      "domainLookupEnd",
+      "connectStart",
+      "connectEnd",
+      "requestStart",
+      "responseStart",
+      "responseEnd",
+    ]);
+  },
+
+  assert_same_origin_redirected_from_cross_origin_resource: entry => {
+    assert_zeroed_(entry, [
+      "workerStart",
+      "redirectStart",
+      "redirectEnd",
+      "domainLookupStart",
+      "domainLookupEnd",
+      "connectStart",
+      "connectEnd",
+      "secureConnectionStart",
+      "requestStart",
+      "responseStart",
+      "transferSize",
+      "encodedBodySize",
+      "decodedBodySize",
+    ]);
+
+    assert_ordered_(entry, [
+      "fetchStart",
+      "responseEnd",
+    ]);
+
+    assert_equals(entry.fetchStart, entry.startTime,
+      "fetchStart must equal startTime");
+  },
+
+  assert_tao_failure_resource: entry => {
+    assert_equals(entry.entryType, "resource", "entryType must always be 'resource'");
+
+    assert_positive_(entry, [
+      "startTime",
+    ]);
+
+    assert_not_negative_(entry, [
+      "duration",
+    ]);
+
+    assert_zeroed_(entry, [
+      "redirectStart",
+      "redirectEnd",
+      "domainLookupStart",
+      "domainLookupEnd",
+      "connectStart",
+      "connectEnd",
+      "secureConnectionStart",
+      "requestStart",
+      "responseStart",
+      "transferSize",
+      "encodedBodySize",
+      "decodedBodySize",
+    ]);
+  }
+
+};
+
+const attribute_test_internal = (loader, path, validator, run_test, test_label) => {
+  promise_test(
+    async () => {
+      let loaded_entry = new Promise((resolve, reject) => {
+        new PerformanceObserver((entry_list, self) => {
+          try {
+            const name_matches = entry_list.getEntries().forEach(entry => {
+              if (entry.name.includes(path)) {
+                resolve(entry);
+              }
+            });
+          } catch(e) {
+            // By surfacing exceptions through the Promise interface, tests can
+            // fail fast with a useful message instead of timing out.
+            reject(e);
+          }
+        }).observe({"type": "resource"});
+      });
+
+      await loader(path, validator);
+      const entry = await(loaded_entry);
+      run_test(entry);
+  }, test_label);
+};
+
+// Given a resource-loader, a path (a relative path or absolute URL), and a
+// PerformanceResourceTiming test, applies the loader to the resource path
+// and tests the resulting PerformanceResourceTiming entry.
+const attribute_test = (loader, path, run_test, test_label) => {
+  attribute_test_internal(loader, path, () => {}, run_test, test_label);
+};
+
+// Similar to attribute test, but on top of that, validates the added element,
+// to ensure the test does what it intends to do.
+const attribute_test_with_validator = (loader, path, validator, run_test, test_label) => {
+  attribute_test_internal(loader, path, validator, run_test, test_label);
+};
+
+const network_error_entry_test = (originalURL, args, label) => {
+  const url = new URL(originalURL, location.href);
+  const search = new URLSearchParams(url.search.substr(1));
+  const timeBefore = performance.now();
+  loader = () => new Promise(resolve => fetch(url, args).catch(resolve));
+
+  attribute_test(
+    loader, url,
+    () => {
+      const timeAfter = performance.now();
+      const names = performance.getEntriesByType('resource').filter(e => e.initiatorType === 'fetch').map(e => e.name);
+      const entries = performance.getEntriesByName(url.toString());
+      assert_equals(entries.length, 1, 'resource timing entry for network error');
+      const entry = entries[0]
+      assert_equals(entry.startTime, entry.fetchStart, 'startTime and fetchStart should be equal');
+      assert_greater_than_equal(entry.startTime, timeBefore, 'startTime and fetchStart should be greater than the time before fetching');
+      assert_greater_than_equal(timeAfter, entry.responseEnd, 'endTime should be less than the time right after returning from the fetch');
+      invariants.assert_tao_failure_resource(entry);
+  }, `A ResourceTiming entry should be created for network error of type ${label}`);
+}
diff --git a/test/fixtures/wpt/resource-timing/resources/fake_responses.html b/test/fixtures/wpt/resource-timing/resources/fake_responses.html
new file mode 100644
index 00000000000000..52cad6c41570e1
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/fake_responses.html
@@ -0,0 +1,19 @@
+<body>
+<script>
+function request(type) {
+  var client = new XMLHttpRequest,
+    identifier = type == "tag" ? Math.random() : new Date().toGMTString(),
+    url = "fake_responses.py?" + type + "=" + identifier
+    client.open("GET", url, false)
+    client.send(null)
+    client.open("GET", url, false)
+    client.setRequestHeader(type == "tag" ? "If-None-Match" : "If-Modified-Since", identifier)
+    client.send(null)
+}
+
+if(window.parent.setup_iframe) {
+  window.parent.setup_iframe();
+  request("tag");
+}
+</script>
+</body>
diff --git a/test/fixtures/wpt/resource-timing/resources/fake_responses_https.sub.html b/test/fixtures/wpt/resource-timing/resources/fake_responses_https.sub.html
new file mode 100644
index 00000000000000..21f1f02a6747f1
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/fake_responses_https.sub.html
@@ -0,0 +1,18 @@
+<body>
+<script>
+function request() {
+  var client = new XMLHttpRequest,
+      baseurl = "https://{{hosts[alt][]}}:{{ports[https][0]}}{{location[pathname]}}",
+      url = new URL("fake_responses.py", baseurl).href;
+    client.open("GET", url, false)
+    client.send(null)
+    client.open("GET", url, false)
+    client.send(null)
+}
+
+if(window.parent.setup_iframe) {
+  window.parent.setup_iframe();
+  request();
+}
+</script>
+</body>
diff --git a/test/fixtures/wpt/resource-timing/resources/fake_responses_https_redirect.sub.html b/test/fixtures/wpt/resource-timing/resources/fake_responses_https_redirect.sub.html
new file mode 100644
index 00000000000000..2ee92b2a5511c0
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/fake_responses_https_redirect.sub.html
@@ -0,0 +1,20 @@
+<body>
+<script>
+function request() {
+  var client = new XMLHttpRequest,
+      baseurl = "http://{{hosts[alt][]}}:{{ports[http][0]}}{{location[pathname]}}",
+      subresource = "fake_responses.py",
+      redirecturl = new URL(subresource, "https://{{hosts[][www]}}:{{ports[https][0]}}{{location[pathname]}}").href,
+      url = new URL(subresource + "?redirect=" + redirecturl, baseurl).href;
+    client.open("GET", url, false)
+    client.send(null)
+    client.open("GET", url, false)
+    client.send(null)
+}
+
+if(window.parent.setup_iframe) {
+  window.parent.setup_iframe();
+  request();
+}
+</script>
+</body>
diff --git a/test/fixtures/wpt/resource-timing/resources/frame-timing.js b/test/fixtures/wpt/resource-timing/resources/frame-timing.js
new file mode 100644
index 00000000000000..e0c364e9b2c3e2
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/frame-timing.js
@@ -0,0 +1,48 @@
+function test_frame_timing_before_load_event(type) {
+    promise_test(async t => {
+        const {document, performance} = type === 'frame' ? window.parent : window;
+        const delay = 500;
+        const frame = document.createElement(type);
+        t.add_cleanup(() => frame.remove());
+        await new Promise(resolve => {
+            frame.addEventListener('load', resolve);
+            frame.src = `resources/iframe-with-delay.sub.html?delay=${delay}`;
+            (type === 'frame' ? document.querySelector('frameset') : document.body).appendChild(frame);
+        });
+
+        const entries = performance.getEntriesByName(frame.src);
+        const navigationEntry = frame.contentWindow.performance.getEntriesByType('navigation')[0];
+        assert_equals(entries.length, 1);
+        assert_equals(entries[0].initiatorType, type);
+        assert_greater_than(performance.now(), entries[0].responseEnd + delay);
+        const domContentLoadedEventAbsoluteTime = navigationEntry.domContentLoadedEventStart + frame.contentWindow.performance.timeOrigin;
+        const frameResponseEndAbsoluteTime = entries[0].responseEnd + performance.timeOrigin;
+        assert_greater_than(domContentLoadedEventAbsoluteTime, frameResponseEndAbsoluteTime);
+    }, `A ${type} should report its RT entry when the response is done and before it is completely loaded`);
+}
+
+
+function test_frame_timing_change_src(type) {
+    promise_test(async t => {
+        const {document, performance} = type === 'frame' ? window.parent : window;
+        const frame = document.createElement(type);
+        t.add_cleanup(() => frame.remove());
+        await new Promise(resolve => {
+          const done = () => {
+            resolve();
+            frame.removeEventListener('load', done);
+          }
+          frame.addEventListener('load', done);
+          frame.src = 'resources/green.html?1';
+            (type === 'frame' ? document.querySelector('frameset') : document.body).appendChild(frame);
+        });
+
+        await new Promise(resolve => {
+          frame.addEventListener('load', resolve);
+          frame.src = 'resources/green.html?2';
+        });
+
+        const entries = performance.getEntries().filter(e => e.name.includes('green.html'));
+        assert_equals(entries.length, 2);
+      }, `A ${type} should report separate RT entries if its src changed from the outside`);
+}
\ No newline at end of file
diff --git a/test/fixtures/wpt/resource-timing/resources/frameset-timing-frame.html b/test/fixtures/wpt/resource-timing/resources/frameset-timing-frame.html
new file mode 100644
index 00000000000000..e260f575268e6c
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/frameset-timing-frame.html
@@ -0,0 +1,8 @@
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="./frame-timing.js"></script>
+
+<script>
+  test_frame_timing_before_load_event('frame');
+  test_frame_timing_change_src('frame');
+</script>
diff --git a/test/fixtures/wpt/resource-timing/resources/green-frame.html b/test/fixtures/wpt/resource-timing/resources/green-frame.html
new file mode 100644
index 00000000000000..9613240ae38789
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/green-frame.html
@@ -0,0 +1,7 @@
+<html>
+  <head>
+    <frameset>
+      <frame src="green.html?id=frame">
+    </frameset>
+  </head>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/resources/green.html b/test/fixtures/wpt/resource-timing/resources/green.html
new file mode 100644
index 00000000000000..b8a1947b77e25a
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/green.html
@@ -0,0 +1,10 @@
+<!DOCTYPE HTML>
+<html>
+    <head>
+        <meta content="text/html; charset=utf-8" http-equiv="Content-Type" />
+        <title>Green Test Page</title>
+    </head>
+    <body style="background-color:#00FF00;">
+        <h1>Placeholder</h1>
+    </body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/resources/green.html.headers b/test/fixtures/wpt/resource-timing/resources/green.html.headers
new file mode 100644
index 00000000000000..cb762eff806849
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/green.html.headers
@@ -0,0 +1 @@
+Access-Control-Allow-Origin: *
diff --git a/test/fixtures/wpt/resource-timing/resources/iframe-TAO-crossorigin-port.sub.html b/test/fixtures/wpt/resource-timing/resources/iframe-TAO-crossorigin-port.sub.html
new file mode 100644
index 00000000000000..97d77fcc58a3bb
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/iframe-TAO-crossorigin-port.sub.html
@@ -0,0 +1,31 @@
+<!DOCTYPE html>
+<html>
+<body>
+<script>
+    const url = '{{location[scheme]}}://{{host}}:{{ports[http][1]}}/resource-timing/resources/TAOResponse.py?tao=origin_port_{{ports[http][1]}}';
+    const observe = (list, observer) => {
+        const entry = list.getEntries()[0];
+        const sum = entry.redirectStart +
+                  entry.redirectEnd +
+                  entry.domainLookupStart +
+                  entry.domainLookupEnd +
+                  entry.connectStart +
+                  entry.connectEnd +
+                  entry.secureConnectionStart +
+                  entry.requestStart +
+                  entry.responseStart +
+                  entry.transferSize +
+                  entry.encodedBodySize +
+                  entry.decodedBodySize;
+
+        const result = sum == 0 ? 'PASS' : 'FAIL';
+        window.top.postMessage(result, '*');
+    }
+    let observer = new PerformanceObserver(observe);
+    observer.observe({ entryTypes: ["resource"] });
+    fetch(url).then(r => r.text());
+</script>
+</body>
+</html>
+
+
diff --git a/test/fixtures/wpt/resource-timing/resources/iframe-load-from-mem-cache-transfer-size.html b/test/fixtures/wpt/resource-timing/resources/iframe-load-from-mem-cache-transfer-size.html
new file mode 100644
index 00000000000000..6f37a33e8c2e83
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/iframe-load-from-mem-cache-transfer-size.html
@@ -0,0 +1,24 @@
+<!DOCTYPE HTML>
+<html>
+
+<head>
+  <meta charset="utf-8" />
+  <title>transfer size of resource timing when loaded from memory cache.</title>
+</head>
+
+<body>
+  <script>
+    // This function is called from the test in the parent document.
+    function getScript(url) {
+      const script = document.createElement("script");
+      const loaded = new Promise(resolve => {
+        script.onload = script.onerror = resolve;
+      });
+      script.src = url;
+      document.body.appendChild(script);
+      return loaded;
+    }
+  </script>
+</body>
+
+</html>
diff --git a/test/fixtures/wpt/resource-timing/resources/iframe-navigate-back.html b/test/fixtures/wpt/resource-timing/resources/iframe-navigate-back.html
new file mode 100644
index 00000000000000..f944b633e2f207
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/iframe-navigate-back.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing iframe navigate - back button navigation</title>
+</head>
+<body onunload="/*disable bfcache*/">
+<script src="/common/get-host-info.sub.js"></script>
+<script src="nested-contexts.js"></script>
+<script>
+  setup_back_navigation("iframe-navigate-back.html");
+</script>
+<iframe id="target"></iframe>
+<script>
+  target.src = pre_navigate_url;
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/resources/iframe-navigate.html b/test/fixtures/wpt/resource-timing/resources/iframe-navigate.html
new file mode 100644
index 00000000000000..02868840218953
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/iframe-navigate.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing iframe navigate</title>
+</head>
+<body>
+<script src="/common/get-host-info.sub.js"></script>
+<script src="nested-contexts.js"></script>
+<script>
+  setup_navigate_test();
+</script>
+<iframe id="target"></iframe>
+<script>
+  target.src = pre_navigate_url;
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/resources/iframe-refresh.html b/test/fixtures/wpt/resource-timing/resources/iframe-refresh.html
new file mode 100644
index 00000000000000..862b96da9dae68
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/iframe-refresh.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing iframe refresh</title>
+</head>
+<body>
+<script src="/common/get-host-info.sub.js"></script>
+<script src="nested-contexts.js"></script>
+<script>
+  setup_refresh_test();
+</script>
+<iframe id="target"></iframe>
+<script>
+  target.src = pre_refresh_url;
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/resources/iframe-reload-TAO.html b/test/fixtures/wpt/resource-timing/resources/iframe-reload-TAO.html
new file mode 100644
index 00000000000000..461f43bf8e27b4
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/iframe-reload-TAO.html
@@ -0,0 +1,25 @@
+<!doctype html>
+<html>
+<head>
+<meta charset="utf-8" />
+<script src="/resources/testharness.js"></script>
+<script src="resource-loaders.js"></script>
+<script src="entry-invariants.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<body>
+<script>
+  const {HTTP_NOTSAMESITE_ORIGIN} = get_host_info();
+  const font_url = `${HTTP_NOTSAMESITE_ORIGIN}/resource-timing/resources/cors-ahem.py`;
+  if (location.hash === '#check') {
+    attribute_test(
+      load.font, font_url,
+      invariants.assert_tao_pass_no_redirect_http,
+      "Test that TAO headers are reused on reloads.");
+  } else {
+    window.onload = () => {
+      location.hash = 'check';
+      location.reload();
+    };
+  }
+</script>
+</body>
diff --git a/test/fixtures/wpt/resource-timing/resources/iframe-setdomain.sub.html b/test/fixtures/wpt/resource-timing/resources/iframe-setdomain.sub.html
new file mode 100644
index 00000000000000..4a2f609aa469f1
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/iframe-setdomain.sub.html
@@ -0,0 +1,14 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <title>domain: {{domains[]}}</title>
+</head>
+<body>
+  <script>
+    // The purpose of this IFrame is to change the 'document.domain'
+    document.domain = "{{domains[]}}";
+  </script>
+  The resource-timings-level1.sub.html test loads this document into an IFrame to vet that setting
+  'document.domain' does not effect the timing allowed.
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/resources/iframe-with-delay.sub.html b/test/fixtures/wpt/resource-timing/resources/iframe-with-delay.sub.html
new file mode 100644
index 00000000000000..fe50aa7e471deb
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/iframe-with-delay.sub.html
@@ -0,0 +1,3 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<img src="/xhr/resources/delay.py?ms={{GET[delay]}}" />
diff --git a/test/fixtures/wpt/resource-timing/resources/iframe_TAO_match_origin.html b/test/fixtures/wpt/resource-timing/resources/iframe_TAO_match_origin.html
new file mode 100644
index 00000000000000..cf68aade7954e6
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/iframe_TAO_match_origin.html
@@ -0,0 +1,21 @@
+<body>
+<script>
+function dirname(path) {
+    return path.replace(/\/[^\/]*$/, '/');
+}
+
+function request() {
+  var dirName = dirname(location.href);
+  var client = new XMLHttpRequest,
+  // create a cross-origin request
+    url = dirName.replace('://', '://www.') + 'TAOResponse.py?tao=match_origin';
+    client.open("GET", url, false);
+    client.send(null);
+}
+
+if(window.parent.setup_iframe) {
+  window.parent.setup_iframe();
+  request();
+}
+</script>
+</body>
diff --git a/test/fixtures/wpt/resource-timing/resources/import.sub.css b/test/fixtures/wpt/resource-timing/resources/import.sub.css
new file mode 100644
index 00000000000000..618c568d2a1d7b
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/import.sub.css
@@ -0,0 +1 @@
+@import "delay-css.py?delay={{GET[delay]}}"
\ No newline at end of file
diff --git a/test/fixtures/wpt/resource-timing/resources/importer.css b/test/fixtures/wpt/resource-timing/resources/importer.css
new file mode 100644
index 00000000000000..771204cdd15402
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/importer.css
@@ -0,0 +1 @@
+@import 'empty_style.css?stylesheet-imported'
\ No newline at end of file
diff --git a/test/fixtures/wpt/resource-timing/resources/importer.js b/test/fixtures/wpt/resource-timing/resources/importer.js
new file mode 100644
index 00000000000000..e73d45da29fb29
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/importer.js
@@ -0,0 +1,2 @@
+import './fake_responses.py?url=empty_script.js?script-head-import-defer';
+import('./fake_responses.py?url=empty_script.js?script-head-import-defer-dynamic').then(module => {});
\ No newline at end of file
diff --git a/test/fixtures/wpt/resource-timing/resources/importer_async.js b/test/fixtures/wpt/resource-timing/resources/importer_async.js
new file mode 100644
index 00000000000000..4b1cd4ddaef46d
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/importer_async.js
@@ -0,0 +1,2 @@
+import './fake_responses.py?url=empty_script.js?script-head-import-async';
+import('./fake_responses.py?url=empty_script.js?script-head-import-async-dynamic').then(module => {});
\ No newline at end of file
diff --git a/test/fixtures/wpt/resource-timing/resources/importer_dynamic.css b/test/fixtures/wpt/resource-timing/resources/importer_dynamic.css
new file mode 100644
index 00000000000000..f0ba069f0c98ab
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/importer_dynamic.css
@@ -0,0 +1 @@
+@import 'empty_style.css?stylesheet-imported-dynamic'
\ No newline at end of file
diff --git a/test/fixtures/wpt/resource-timing/resources/importer_print.css b/test/fixtures/wpt/resource-timing/resources/importer_print.css
new file mode 100644
index 00000000000000..aac191635ed520
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/importer_print.css
@@ -0,0 +1 @@
+@import 'empty_style.css?stylesheet-imported-print'
\ No newline at end of file
diff --git a/test/fixtures/wpt/resource-timing/resources/inject_resource_test.html b/test/fixtures/wpt/resource-timing/resources/inject_resource_test.html
new file mode 100644
index 00000000000000..44d09675d38e26
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/inject_resource_test.html
@@ -0,0 +1,7 @@
+<body>
+<script>
+if(window.parent.setup_iframe) {
+  window.parent.setup_iframe();
+}
+</script>
+</body>
diff --git a/test/fixtures/wpt/resource-timing/resources/invalid.jpg b/test/fixtures/wpt/resource-timing/resources/invalid.jpg
new file mode 100644
index 00000000000000..81c545efebe5f5
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/invalid.jpg
@@ -0,0 +1 @@
+1234
diff --git a/test/fixtures/wpt/resource-timing/resources/manifest.json b/test/fixtures/wpt/resource-timing/resources/manifest.json
new file mode 100644
index 00000000000000..e107c044d5d8a8
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/manifest.json
@@ -0,0 +1,4 @@
+{
+    "name": "Dummy manifest",
+    "start_url": "/start.html"
+}
diff --git a/test/fixtures/wpt/resource-timing/resources/navigate_back.html b/test/fixtures/wpt/resource-timing/resources/navigate_back.html
new file mode 100644
index 00000000000000..345eee1fccca5c
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/navigate_back.html
@@ -0,0 +1,7 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<script>
+window.onload = function() {history.back();}
+</script>
diff --git a/test/fixtures/wpt/resource-timing/resources/nested-contexts.js b/test/fixtures/wpt/resource-timing/resources/nested-contexts.js
new file mode 100644
index 00000000000000..c0822943e86a68
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/nested-contexts.js
@@ -0,0 +1,110 @@
+let destination = location;
+
+if (location.search == "?cross-site") {
+    const https = destination.protocol.startsWith("https");
+    destination = get_host_info()[https ? 'HTTPS_NOTSAMESITE_ORIGIN' : 'HTTP_NOTSAMESITE_ORIGIN'];
+} else if (location.search == "?crossorigin") {
+    destination =  get_host_info().REMOTE_ORIGIN;
+}
+
+const pre_navigate_url =
+  new URL("/resource-timing/resources/document-that-navigates.html",
+    destination).href;
+const post_navigate_url =
+  new URL("/resource-timing/resources/document-navigated.html",
+    destination).href;
+const pre_refresh_url =
+  new URL("/resource-timing/resources/document-that-refreshes.html",
+    destination).href;
+const post_refresh_url =
+  new URL("/resource-timing/resources/document-refreshed.html",
+    destination).href;
+
+const setup_navigate_or_refresh = (type, pre, post) => {
+  const verify_document_navigate_not_observable = () => {
+    const entries = performance.getEntriesByType("resource");
+    let found_first_document = false;
+    for (entry of entries) {
+      if (entry.name == pre) {
+        found_first_document = true;
+      }
+      if (entry.name == post) {
+        opener.postMessage(`FAIL - ${type} document should not be observable`,
+          `*`);
+        return;
+      }
+    }
+    if (!found_first_document) {
+      opener.postMessage("FAIL - initial document should be observable", "*");
+      return;
+    }
+    opener.postMessage("PASS", "*");
+  }
+  window.addEventListener("message", e => {
+    if (e.data == type) {
+      verify_document_navigate_not_observable();
+    }
+  });
+}
+
+const setup_navigate_test = () => {
+  setup_navigate_or_refresh("navigated", pre_navigate_url, post_navigate_url);
+}
+
+const setup_refresh_test = () => {
+  setup_navigate_or_refresh("refreshed", pre_refresh_url, post_refresh_url);
+}
+
+const setup_back_navigation = pushed_url => {
+  const verify_document_navigate_not_observable = navigated_back => {
+    const entries = performance.getEntriesByType("resource");
+    let found_first_document = false;
+    for (entry of entries) {
+      if (entry.name == pre_navigate_url) {
+        found_first_document = true;
+      }
+      if (entry.name == post_navigate_url) {
+        opener.postMessage("FAIL - navigated document exposed", "*");
+        return;
+      }
+    }
+    if (!found_first_document) {
+      opener.postMessage(`FAIL - first document not exposed. navigated_back ` +
+        `is ${navigated_back}`, "*");
+      return;
+    }
+    if (navigated_back) {
+      opener.postMessage("PASS", "*");
+    }
+  }
+  window.addEventListener("message", e => {
+    if (e.data == "navigated") {
+      verify_document_navigate_not_observable(sessionStorage.navigated);
+      if (sessionStorage.navigated) {
+        delete sessionStorage.navigated;
+      } else {
+        sessionStorage.navigated = true;
+        setTimeout(() => {
+          history.pushState({}, "", pushed_url);
+          location.href="navigate_back.html";
+        }, 0);
+      }
+    }
+  });
+}
+
+const open_test_window = (url, message) => {
+  promise_test(() => {
+    return new Promise((resolve, reject) => {
+      const openee = window.open(url);
+      addEventListener("message", e => {
+        openee.close();
+        if (e.data == "PASS") {
+          resolve();
+        } else {
+          reject(e.data);
+        }
+      });
+    });
+  }, message);
+}
diff --git a/test/fixtures/wpt/resource-timing/resources/nested.css b/test/fixtures/wpt/resource-timing/resources/nested.css
new file mode 100644
index 00000000000000..90d61b04acc444
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/nested.css
@@ -0,0 +1,10 @@
+@import "resource_timing_test0.css?id=n1";
+
+@font-face {
+    font-family: remoteFont;
+    src: url('/fonts/Ahem.ttf?id=n1');
+}
+ol {
+    font-family: remoteFont;
+    list-style-image: url('blue.png?id=n1');
+}
diff --git a/test/fixtures/wpt/resource-timing/resources/notify_parent.html b/test/fixtures/wpt/resource-timing/resources/notify_parent.html
new file mode 100644
index 00000000000000..c104f3c8f0695a
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/notify_parent.html
@@ -0,0 +1,4 @@
+<!DOCTYPE html>
+<script>
+window.parent.subFrameLoaded();
+</script>
diff --git a/test/fixtures/wpt/resource-timing/resources/object-navigate-back.html b/test/fixtures/wpt/resource-timing/resources/object-navigate-back.html
new file mode 100644
index 00000000000000..a746947818ffb4
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/object-navigate-back.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing object navigate - back button navigation</title>
+</head>
+<body onunload="/*disable bfcache*/">
+<script src="/common/get-host-info.sub.js"></script>
+<script src="nested-contexts.js"></script>
+<script>
+  setup_back_navigation("object-navigate-back.html");
+</script>
+<object id="target" type="text/html"></object>
+<script>
+  target.data = pre_navigate_url;
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/resources/object-navigate.html b/test/fixtures/wpt/resource-timing/resources/object-navigate.html
new file mode 100644
index 00000000000000..6b4bb3128ee6f1
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/object-navigate.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing object navigate</title>
+</head>
+<body>
+<script src="/common/get-host-info.sub.js"></script>
+<script src="nested-contexts.js"></script>
+<script>
+  setup_navigate_test();
+</script>
+<object id="target" type="text/html"></object>
+<script>
+  target.data = pre_navigate_url;
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/resources/object-refresh.html b/test/fixtures/wpt/resource-timing/resources/object-refresh.html
new file mode 100644
index 00000000000000..5c5f60fb06851a
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/object-refresh.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing object refresh</title>
+</head>
+<body>
+<script src="/common/get-host-info.sub.js"></script>
+<script src="nested-contexts.js"></script>
+<script>
+  setup_refresh_test();
+</script>
+<object id="target" type="text/html"></object>
+<script>
+  target.data = pre_refresh_url;
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/resources/observe-entry.js b/test/fixtures/wpt/resource-timing/resources/observe-entry.js
new file mode 100644
index 00000000000000..260b5929a5bb78
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/observe-entry.js
@@ -0,0 +1,25 @@
+// Given a resource name, returns a promise that will resolve to the
+// corresponding PerformanceResourceTiming entry. The promise will reject,
+// however, if the PerformanceResourceTiming entry isn't observed within ~2
+// seconds (scaled according to WPT timeout scaling).
+const observe_entry = entry_name => {
+  const entry = new Promise(resolve => {
+    new PerformanceObserver((entry_list, observer) => {
+      for (const entry of entry_list.getEntries()) {
+        if (entry.name.endsWith(entry_name)) {
+          resolve(entry);
+          observer.disconnect();
+          return;
+        }
+      }
+    }).observe({"type": "resource", "buffered": true});
+  });
+  const timeout = new Promise((resolve, reject) => {
+    step_timeout(() => {
+      reject(new Error("observe_entry: timeout"));
+    }, 2000);
+  });
+  // If the entry isn't observed within 2 seconds, assume it will never show
+  // up.
+  return Promise.race([entry, timeout]);
+};
diff --git a/test/fixtures/wpt/resource-timing/resources/resource-loaders.js b/test/fixtures/wpt/resource-timing/resources/resource-loaders.js
new file mode 100644
index 00000000000000..99a2c28d2b3b27
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/resource-loaders.js
@@ -0,0 +1,133 @@
+const load = {
+  _cache_bust_value: Math.random().toString().substr(2),
+
+  cache_bust: path => {
+    let url = new URL(path, location.origin);
+    url.href += (url.href.includes("?")) ? '&' : '?';
+    url.href += "unique=" + load._cache_bust_value++
+    return url.href;
+  },
+
+  // Returns a promise that settles once the given path has been fetched as an
+  // image resource.
+  image: path => {
+    return new Promise(resolve => {
+      const img = new Image();
+      img.onload = img.onerror = resolve;
+      img.src = load.cache_bust(path);
+    });
+  },
+
+  // Returns a promise that settles once the given path has been fetched as a
+  // font resource.
+  font: path => {
+    const div = document.createElement('div');
+    div.innerHTML = `
+      <style>
+      @font-face {
+          font-family: ahem;
+          src: url('${load.cache_bust(path)}');
+      }
+      </style>
+      <div style="font-family: ahem;">This fetches ahem font.</div>
+    `;
+    document.body.appendChild(div);
+    return document.fonts.ready.then(() => {
+      document.body.removeChild(div);
+    });
+  },
+
+  // Returns a promise that settles once the given path has been fetched as a
+  // stylesheet resource.
+  stylesheet: async path => {
+    const link = document.createElement("link");
+    link.rel = "stylesheet";
+    link.type = "text/css";
+    link.href = load.cache_bust(path);
+
+    const loaded = new Promise(resolve => {
+      link.onload = link.onerror = resolve;
+    });
+
+    document.head.appendChild(link);
+    await loaded;
+    document.head.removeChild(link);
+  },
+
+  iframe_with_attrs: async (path, attribute_map, validator) => {
+    const frame = document.createElement("iframe");
+    if (attribute_map instanceof Object) {
+      for (const [key, value] of Object.entries(attribute_map)) {
+        frame[key] = value;
+      }
+    }
+    const loaded = new Promise(resolve => {
+      frame.onload = frame.onerror = resolve;
+    });
+    frame.src = load.cache_bust(path);
+    document.body.appendChild(frame);
+    await loaded;
+    if (validator instanceof Function) {
+      validator(frame);
+    }
+    document.body.removeChild(frame);
+  },
+
+  // Returns a promise that settles once the given path has been fetched as an
+  // iframe.
+  iframe: async (path, validator) => {
+    return load.iframe_with_attrs(path, undefined, validator);
+  },
+
+  // Returns a promise that settles once the given path has been fetched as a
+  // script.
+  script: async path => {
+    const script = document.createElement("script");
+    const loaded = new Promise(resolve => {
+      script.onload = script.onerror = resolve;
+    });
+    script.src = load.cache_bust(path);
+    document.body.appendChild(script);
+    await loaded;
+    document.body.removeChild(script);
+  },
+
+  // Returns a promise that settles once the given path has been fetched as an
+  // object.
+  object: async (path, type) => {
+    const object = document.createElement("object");
+    const loaded = new Promise(resolve => {
+      object.onload = object.onerror = resolve;
+    });
+    object.data = load.cache_bust(path);
+    if (type) {
+      object.type = type;
+    }
+    object.style = "width: 0px; height: 0px";
+    document.body.appendChild(object);
+    await loaded;
+    document.body.removeChild(object);
+  },
+
+  // Returns a promise that settles once the given path has been fetched
+  // through a synchronous XMLHttpRequest.
+  xhr_sync: async (path, headers) => {
+    const xhr = new XMLHttpRequest;
+    xhr.open("GET", path, /* async = */ false);
+    if (headers instanceof Object) {
+      for (const [key, value] of Object.entries(headers)) {
+        xhr.setRequestHeader(key, value);
+      }
+    }
+    xhr.send();
+  },
+
+  xhr_async: path => {
+    const xhr = new XMLHttpRequest();
+    xhr.open("GET", path)
+    xhr.send();
+    return new Promise(resolve => {
+      xhr.onload = xhr.onerror = resolve;
+    });
+  }
+};
diff --git a/test/fixtures/wpt/resource-timing/resources/resource_timing_test0.css b/test/fixtures/wpt/resource-timing/resources/resource_timing_test0.css
new file mode 100644
index 00000000000000..8bc8326ba675ad
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/resource_timing_test0.css
@@ -0,0 +1,4 @@
+div#resource_link_css
+{
+    color:hotpink;
+}
\ No newline at end of file
diff --git a/test/fixtures/wpt/resource-timing/resources/resource_timing_test0.html b/test/fixtures/wpt/resource-timing/resources/resource_timing_test0.html
new file mode 100644
index 00000000000000..167c65c5c45d11
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/resource_timing_test0.html
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<html>
+    <head>
+        <title>
+        Child Frame
+        </title>
+    </head>
+    <body style="background-color: #C0C0C0">
+
+        <h1>
+        Child Document
+        </h1>
+
+    </body>
+</html>
\ No newline at end of file
diff --git a/test/fixtures/wpt/resource-timing/resources/resource_timing_test0.js b/test/fixtures/wpt/resource-timing/resources/resource_timing_test0.js
new file mode 100644
index 00000000000000..cf1c1df3920002
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/resource_timing_test0.js
@@ -0,0 +1,3 @@
+// This is a test script for purposes of testing the
+// script initiator type in the Resource Timing feature
+var testDummyValue = 0;
diff --git a/test/fixtures/wpt/resource-timing/resources/resource_timing_test0.js.headers b/test/fixtures/wpt/resource-timing/resources/resource_timing_test0.js.headers
new file mode 100644
index 00000000000000..308bee94d0e47a
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/resource_timing_test0.js.headers
@@ -0,0 +1,2 @@
+Content-Type: text/javascript
+Cache-Control: max-age=36000
diff --git a/test/fixtures/wpt/resource-timing/resources/resource_timing_test0.png b/test/fixtures/wpt/resource-timing/resources/resource_timing_test0.png
new file mode 100644
index 0000000000000000000000000000000000000000..be211bc377180386eec7e891485e083a2c45841e
GIT binary patch
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z><G`3T7`Aa$Eu#m-rw<9;=bmbCwtWHc3Qt|2%Ns_%GUpaAN}?SzdvIAQtHLDn@9CZ
zH?GcJ5S=Ez`^wRE>l*WB#=Z#>-@S`%S8CZt@7Oo5h)`6&={0M#tksJI@9JEj%NRUe
L{an^LB{Ts5<eg&&

literal 0
HcmV?d00001

diff --git a/test/fixtures/wpt/resource-timing/resources/resource_timing_test0.xml b/test/fixtures/wpt/resource-timing/resources/resource_timing_test0.xml
new file mode 100644
index 00000000000000..91cd676be6e6f1
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/resource_timing_test0.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="ISO-8859-1"?>
+<TESTDATA>
+    <ITEM>
+        <DATA>Test XML Data</DATA>
+    </ITEM>
+</TESTDATA>
diff --git a/test/fixtures/wpt/resource-timing/resources/self_navigation.html b/test/fixtures/wpt/resource-timing/resources/self_navigation.html
new file mode 100644
index 00000000000000..beb12f5da55178
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/self_navigation.html
@@ -0,0 +1 @@
+<meta http-equiv="refresh" content="0;url=notify_parent.html?redirected">
diff --git a/test/fixtures/wpt/resource-timing/resources/shared-worker.js b/test/fixtures/wpt/resource-timing/resources/shared-worker.js
new file mode 100644
index 00000000000000..f3ef3feb964cb7
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/shared-worker.js
@@ -0,0 +1,3 @@
+self.onconnect = e => {
+  e.ports[0].postMessage(performance.timeOrigin);
+}
\ No newline at end of file
diff --git a/test/fixtures/wpt/resource-timing/resources/sizes-helper.js b/test/fixtures/wpt/resource-timing/resources/sizes-helper.js
new file mode 100644
index 00000000000000..86336686b32902
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/sizes-helper.js
@@ -0,0 +1,16 @@
+// Header size is a fixed constant.
+// https://w3c.github.io/resource-timing/#dom-performanceresourcetiming-transfersize
+const headerSize = 300;
+
+const cacheBustUrl = url => {
+  return url + '&unique=' + Math.random().toString().substring(2);
+}
+
+const checkSizeFields = (entry, bodySize, transferSize) => {
+  assert_equals(entry.decodedBodySize, bodySize,
+                'decodedBodySize');
+  assert_equals(entry.encodedBodySize, bodySize,
+                'encodedBodySize');
+  assert_equals(entry.transferSize, transferSize,
+                'transferSize');
+}
diff --git a/test/fixtures/wpt/resource-timing/resources/sw-install.html b/test/fixtures/wpt/resource-timing/resources/sw-install.html
new file mode 100644
index 00000000000000..3d1407e83188ae
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/sw-install.html
@@ -0,0 +1,58 @@
+<!DOCTYPE html>
+<script>
+const service_worker_unregister = async scope => {
+  const absoluteScope = new URL(scope, window.location).href;
+  const registration = await navigator.serviceWorker.getRegistration(scope);
+  if (registration && registration.scope === absoluteScope) {
+    return registration.unregister();
+  }
+};
+
+const service_worker_reregister = async (url, scope) => {
+  if (!scope || scope.length == 0) {
+    return Promise.reject(new Error('tests must define a scope'));
+  }
+
+  await service_worker_unregister(scope);
+  return navigator.serviceWorker.register(url, {'scope': scope});
+};
+
+const wait_for_state_activated = worker => {
+  if (worker.state === 'activated')
+    return Promise.resolve();
+
+  if (worker.state === 'redundant') {
+    return Promise.reject(new Error('worker is redundant'));
+  }
+
+  return new Promise(function(resolve) {
+    worker.addEventListener('statechange', () => {
+      if (worker.state === 'activated') {
+        resolve();
+      }
+    });
+  });
+};
+
+(async () => {
+  const script = '/resource-timing/resources/sw.js';
+  const scope = '/resource-timing/resources/';
+  const registration = await service_worker_reregister(script, scope);
+  await wait_for_state_activated(registration.installing);
+
+  const opener = window.opener;
+  if (!opener) {
+    return;
+  }
+
+  opener.postMessage("installed", "*");
+  window.addEventListener("message", async e => {
+    if (e.data === "unregister") {
+      await registration.unregister();
+      opener.postMessage("unregistered", "*");
+    }
+  });
+
+})();
+
+</script>
diff --git a/test/fixtures/wpt/resource-timing/resources/sw.js b/test/fixtures/wpt/resource-timing/resources/sw.js
new file mode 100644
index 00000000000000..4e4fe1e1f068fd
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/sw.js
@@ -0,0 +1,3 @@
+self.addEventListener('fetch', function(event) {
+  event.respondWith(fetch(event.request));
+});
diff --git a/test/fixtures/wpt/resource-timing/resources/tao-response.js b/test/fixtures/wpt/resource-timing/resources/tao-response.js
new file mode 100644
index 00000000000000..2194c5d43a5413
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/tao-response.js
@@ -0,0 +1,13 @@
+const tao_response = (tao_value, base_url) => {
+  const payload = {
+    'headers': {
+      'Timing-Allow-Origin': tao_value
+    }
+  };
+  return custom_cors_response(payload, base_url);
+};
+
+const remote_tao_response = tao_value => {
+  const {REMOTE_ORIGIN} = get_host_info();
+  return tao_response(tao_value, REMOTE_ORIGIN);
+};
diff --git a/test/fixtures/wpt/resource-timing/resources/webperftestharness.js b/test/fixtures/wpt/resource-timing/resources/webperftestharness.js
new file mode 100644
index 00000000000000..869ef3d74f77b5
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/webperftestharness.js
@@ -0,0 +1,166 @@
+/*
+author: W3C http://www.w3.org/
+help: http://www.w3.org/TR/navigation-timing/#sec-window.performance-attribute
+*/
+//
+// Helper Functions for ResourceTiming W3C tests
+//
+
+var performanceNamespace = window.performance;
+var timingAttributes = [
+    'connectEnd',
+    'connectStart',
+    'domComplete',
+    'domContentLoadedEventEnd',
+    'domContentLoadedEventStart',
+    'domInteractive',
+    'domLoading',
+    'domainLookupEnd',
+    'domainLookupStart',
+    'fetchStart',
+    'loadEventEnd',
+    'loadEventStart',
+    'navigationStart',
+    'redirectEnd',
+    'redirectStart',
+    'requestStart',
+    'responseEnd',
+    'responseStart',
+    'unloadEventEnd',
+    'unloadEventStart'
+];
+
+var namespace_check = false;
+
+//
+// All test() functions in the WebPerf test suite should use wp_test() instead.
+//
+// wp_test() validates the window.performance namespace exists prior to running tests and
+// immediately shows a single failure if it does not.
+//
+
+function wp_test(func, msg, properties)
+{
+    // only run the namespace check once
+    if (!namespace_check)
+    {
+        namespace_check = true;
+
+        if (performanceNamespace === undefined || performanceNamespace == null)
+        {
+            // show a single error that window.performance is undefined
+            // The window.performance attribute provides a hosting area for performance related attributes.
+            test(function() { assert_true(performanceNamespace !== undefined && performanceNamespace != null, "window.performance is defined and not null"); }, "window.performance is defined and not null.");
+        }
+    }
+
+    test(func, msg, properties);
+}
+
+function test_namespace(child_name, skip_root)
+{
+    if (skip_root === undefined) {
+        var msg = 'window.performance is defined';
+        // The window.performance attribute provides a hosting area for performance related attributes.
+        wp_test(function () { assert_not_equals(performanceNamespace, undefined, msg); }, msg);
+    }
+
+    if (child_name !== undefined) {
+        var msg2 = 'window.performance.' + child_name + ' is defined';
+        // The window.performance attribute provides a hosting area for performance related attributes.
+        wp_test(function() { assert_not_equals(performanceNamespace[child_name], undefined, msg2); }, msg2);
+    }
+}
+
+function test_attribute_exists(parent_name, attribute_name, properties)
+{
+    var msg = 'window.performance.' + parent_name + '.' + attribute_name + ' is defined.';
+    wp_test(function() { assert_not_equals(performanceNamespace[parent_name][attribute_name], undefined, msg); }, msg, properties);
+}
+
+function test_enum(parent_name, enum_name, value, properties)
+{
+    var msg = 'window.performance.' + parent_name + '.' + enum_name + ' is defined.';
+    wp_test(function() { assert_not_equals(performanceNamespace[parent_name][enum_name], undefined, msg); }, msg, properties);
+
+    msg = 'window.performance.' + parent_name + '.' + enum_name + ' = ' + value;
+    wp_test(function() { assert_equals(performanceNamespace[parent_name][enum_name], value, msg); }, msg, properties);
+}
+
+function test_timing_order(attribute_name, greater_than_attribute, properties)
+{
+    // ensure it's not 0 first
+    var msg = "window.performance.timing." + attribute_name + " > 0";
+    wp_test(function() { assert_true(performanceNamespace.timing[attribute_name] > 0, msg); }, msg, properties);
+
+    // ensure it's in the right order
+    msg = "window.performance.timing." + attribute_name + " >= window.performance.timing." + greater_than_attribute;
+    wp_test(function() { assert_true(performanceNamespace.timing[attribute_name] >= performanceNamespace.timing[greater_than_attribute], msg); }, msg, properties);
+}
+
+function test_timing_greater_than(attribute_name, greater_than, properties)
+{
+    var msg = "window.performance.timing." + attribute_name + " > " + greater_than;
+    test_greater_than(performanceNamespace.timing[attribute_name], greater_than, msg, properties);
+}
+
+function test_timing_equals(attribute_name, equals, msg, properties)
+{
+    var test_msg = msg || "window.performance.timing." + attribute_name + " == " + equals;
+    test_equals(performanceNamespace.timing[attribute_name], equals, test_msg, properties);
+}
+
+//
+// Non-test related helper functions
+//
+
+function sleep_milliseconds(n)
+{
+    var start = new Date().getTime();
+    while (true) {
+        if ((new Date().getTime() - start) >= n) break;
+    }
+}
+
+//
+// Common helper functions
+//
+
+function test_true(value, msg, properties)
+{
+    wp_test(function () { assert_true(value, msg); }, msg, properties);
+}
+
+function test_equals(value, equals, msg, properties)
+{
+    wp_test(function () { assert_equals(value, equals, msg); }, msg, properties);
+}
+
+function test_greater_than(value, greater_than, msg, properties)
+{
+    wp_test(function () { assert_true(value > greater_than, msg); }, msg, properties);
+}
+
+function test_greater_or_equals(value, greater_than, msg, properties)
+{
+    wp_test(function () { assert_true(value >= greater_than, msg); }, msg, properties);
+}
+
+function test_not_equals(value, notequals, msg, properties)
+{
+    wp_test(function() { assert_not_equals(value, notequals, msg); }, msg, properties);
+}
+
+function test_tao_pass(entry) {
+    test_greater_than(entry.redirectStart, 0, 'redirectStart > 0 in cross-origin redirect with Timing-Allow-Origin.');
+    test_greater_than(entry.redirectEnd, 0, 'redirectEnd > 0 in cross-origin redirect with Timing-Allow-Origin.');
+    test_greater_than(entry.fetchStart, 0, 'fetchStart > 0 in cross-origin redirect with Timing-Allow-Origin.');
+    test_greater_than(entry.fetchStart, entry.startTime, 'startTime < fetchStart in cross-origin redirect with Timing-Allow-Origin.');
+}
+
+function test_tao_fail(entry) {
+    test_equals(entry.redirectStart, 0, 'redirectStart == 0 in cross-origin redirect with failing Timing-Allow-Origin.');
+    test_equals(entry.redirectEnd, 0, 'redirectEnd == 0 in cross-origin redirect with failing Timing-Allow-Origin.');
+    test_greater_than(entry.fetchStart, 0, 'fetchStart > 0 in cross-origin redirect with failing Timing-Allow-Origin.');
+    test_equals(entry.fetchStart, entry.startTime, 'startTime == fetchStart in cross-origin redirect with failing Timing-Allow-Origin.');
+}
diff --git a/test/fixtures/wpt/resource-timing/resources/webperftestharnessextension.js b/test/fixtures/wpt/resource-timing/resources/webperftestharnessextension.js
new file mode 100644
index 00000000000000..dc02c075b3d07f
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/webperftestharnessextension.js
@@ -0,0 +1,188 @@
+//
+// Helper functions for Resource Timing tests
+//
+
+var mark_names = [
+    '',
+    '1',
+    'abc',
+];
+
+var measures = [
+    [''],
+    ['2', 1],
+    ['aaa', 'navigationStart', ''],
+];
+
+function test_method_exists(method, method_name, properties)
+{
+    var msg;
+    if (typeof method === 'function')
+        msg = 'performance.' + method.name + ' is supported!';
+    else
+        msg = 'performance.' + method_name + ' is supported!';
+    wp_test(function() { assert_equals(typeof method, 'function', msg); }, msg, properties);
+}
+
+function test_noless_than(value, greater_than, msg, properties)
+{
+    wp_test(function () { assert_true(value >= greater_than, msg); }, msg, properties);
+}
+
+function test_fail(msg, properties)
+{
+    wp_test(function() { assert_unreached(); }, msg, properties);
+}
+
+function test_resource_entries(entries, expected_entries)
+{
+    test(function() {
+        // This is slightly convoluted so that we can sort the output.
+        var actual_entries = {};
+        var origin = window.location.protocol + "//" + window.location.host;
+
+        for (var i = 0; i < entries.length; ++i) {
+            var entry = entries[i];
+            var found = false;
+            for (var expected_entry in expected_entries) {
+                if (entry.name == origin + expected_entry) {
+                    found = true;
+                    if (expected_entry in actual_entries) {
+                        assert_unreached(expected_entry + ' is not expected to have duplicate entries');
+                    }
+                    actual_entries[expected_entry] = entry;
+                    break;
+                }
+            }
+            if (!found) {
+                assert_unreached(entries[i].name + ' is not expected to be in the Resource Timing buffer');
+            }
+        }
+
+        sorted_urls = [];
+        for (var i in actual_entries) {
+            sorted_urls.push(i);
+        }
+        sorted_urls.sort();
+        for (var i in sorted_urls) {
+            var url = sorted_urls[i];
+            assert_equals(actual_entries[url].initiatorType,
+                        expected_entries[url],
+                        origin + url + ' is expected to have initiatorType ' + expected_entries[url]);
+        }
+        for (var j in expected_entries) {
+            if (!(j in actual_entries)) {
+                assert_unreached(origin + j + ' is expected to be in the Resource Timing buffer');
+            }
+        }
+    }, "Testing resource entries");
+}
+
+function performance_entrylist_checker(type)
+{
+    var entryType = type;
+
+    function entry_check(entry, expectedNames)
+    {
+        var msg = 'Entry \"' + entry.name + '\" should be one that we have set.';
+        wp_test(function() { assert_in_array(entry.name, expectedNames, msg); }, msg);
+        test_equals(entry.entryType, entryType, 'entryType should be \"' + entryType + '\".');
+        if (type === "measure") {
+            test_true(isFinite(entry.startTime), 'startTime should be a number.');
+            test_true(isFinite(entry.duration), 'duration should be a number.');
+        } else if (type === "mark") {
+            test_greater_than(entry.startTime, 0, 'startTime should greater than 0.');
+            test_equals(entry.duration, 0, 'duration of mark should be 0.');
+        }
+    }
+
+    function entrylist_order_check(entryList)
+    {
+        var inOrder = true;
+        for (var i = 0; i < entryList.length - 1; ++i)
+        {
+            if (entryList[i + 1].startTime < entryList[i].startTime) {
+                inOrder = false;
+                break;
+            }
+        }
+        return inOrder;
+    }
+
+    function entrylist_check(entryList, expectedLength, expectedNames)
+    {
+        test_equals(entryList.length, expectedLength, 'There should be ' + expectedLength + ' entries.');
+        test_true(entrylist_order_check(entryList), 'Entries in entrylist should be in order.');
+        for (var i = 0; i < entryList.length; ++i)
+        {
+            entry_check(entryList[i], expectedNames);
+        }
+    }
+
+    return{"entrylist_check":entrylist_check};
+}
+
+function PerformanceContext(context)
+{
+    this.performanceContext = context;
+}
+
+PerformanceContext.prototype = {
+    initialMeasures: function(item, index, array)
+    {
+        this.performanceContext.measure.apply(this.performanceContext, item);
+    },
+
+    mark: function()
+    {
+        this.performanceContext.mark.apply(this.performanceContext, arguments);
+    },
+
+    measure: function()
+    {
+        this.performanceContext.measure.apply(this.performanceContext, arguments);
+    },
+
+    clearMarks: function()
+    {
+        this.performanceContext.clearMarks.apply(this.performanceContext, arguments);
+
+    },
+
+    clearMeasures: function()
+    {
+        this.performanceContext.clearMeasures.apply(this.performanceContext, arguments);
+
+    },
+
+    getEntries: function()
+    {
+        return this.performanceContext.getEntries.apply(this.performanceContext, arguments);
+    },
+
+    getEntriesByType: function()
+    {
+        return this.performanceContext.getEntriesByType.apply(this.performanceContext, arguments);
+    },
+
+    getEntriesByName: function()
+    {
+        return this.performanceContext.getEntriesByName.apply(this.performanceContext, arguments);
+    },
+
+    setResourceTimingBufferSize: function()
+    {
+        return this.performanceContext.setResourceTimingBufferSize.apply(this.performanceContext, arguments);
+    },
+
+    registerResourceTimingBufferFullCallback: function(func)
+    {
+        this.performanceContext.onresourcetimingbufferfull = func;
+    },
+
+    clearResourceTimings: function()
+    {
+        this.performanceContext.clearResourceTimings.apply(this.performanceContext, arguments);
+    }
+
+};
diff --git a/test/fixtures/wpt/resource-timing/resources/worker_with_images.js b/test/fixtures/wpt/resource-timing/resources/worker_with_images.js
new file mode 100644
index 00000000000000..1fa4893201ee00
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/resources/worker_with_images.js
@@ -0,0 +1,22 @@
+let numComplete = 0;
+
+function checkDone() {
+  ++numComplete;
+  if (numComplete == 2) {
+    const numEntries = performance.getEntries().length;
+    postMessage(numEntries);
+  }
+}
+
+function makeRequest(request) {
+  var xhr = new XMLHttpRequest;
+  xhr.open('get', request, true);
+  xhr.onreadystatechange = function() {
+    if (xhr.readyState == 4) {
+      checkDone();
+    }
+  }
+  xhr.send();
+}
+makeRequest('blue.png');
+makeRequest('resource_timing_test0.png');
diff --git a/test/fixtures/wpt/resource-timing/same-origin-from-cross-origin-redirect.html b/test/fixtures/wpt/resource-timing/same-origin-from-cross-origin-redirect.html
new file mode 100644
index 00000000000000..8740b81b13fd8a
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/same-origin-from-cross-origin-redirect.html
@@ -0,0 +1,31 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>This test validates resource timing information for a same-origin
+resource fetched through a cross-origin redirect chain.</title>
+<link rel="author" title="Google" href="https://google.com/" />
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#sec-performanceresourcetiming"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<script src="resources/resource-loaders.js"></script>
+<script src="resources/entry-invariants.js"></script>
+</head>
+<body>
+<script>
+const {HTTP_REMOTE_ORIGIN} = get_host_info();
+let destUrl = `${HTTP_REMOTE_ORIGIN}/resource-timing/resources/multi_redirect.py?`;
+destUrl += `page_origin=http://${document.location.host}`;
+destUrl += `&cross_origin=${HTTP_REMOTE_ORIGIN}`;
+destUrl += `&final_resource=/resource-timing/resources/blank-with-tao.html`;
+
+attribute_test(
+  load.iframe, destUrl,
+  invariants.assert_same_origin_redirected_from_cross_origin_resource,
+  "Verify that cross origin resources' timings are exposed when the final " +
+  "resource at the end of an HTTP redirect chain is same-origin.");
+
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/script-rt-entries.html b/test/fixtures/wpt/resource-timing/script-rt-entries.html
new file mode 100644
index 00000000000000..cdd72bd1e25199
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/script-rt-entries.html
@@ -0,0 +1,37 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing Entry Sequence of Events for Scripts</title>
+<link rel="help" href="https://w3c.github.io/resource-timing/"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<script>
+    async_test(t => {
+        const script = document.createElement("script");
+        const url = new URL('resources/empty.js', location.href).toString();
+        script.addEventListener('load', t.step_func(() => {
+            assert_equals(performance.getEntriesByName(url).length, 1);
+            t.done();
+        }));
+        script.src = url;
+        document.body.appendChild(script);
+        t.add_cleanup(() => script.remove());
+    }, "The RT entry for script should be available when the script 'load' event fires");
+
+    async_test(t => {
+        const script = document.createElement("script");
+        const url = new URL('resources/non-existent.js', location.href).toString();
+        script.addEventListener('error', t.step_func(() => {
+            assert_equals(performance.getEntriesByName(url).length, 1);
+            t.done();
+        }));
+        script.src = url;
+        document.body.appendChild(script);
+        t.add_cleanup(() => script.remove());
+    }, "The RT entry for a non-existent script should be available when the script 'error' event fires");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/secure-iframe-in-insecure-context.html b/test/fixtures/wpt/resource-timing/secure-iframe-in-insecure-context.html
new file mode 100644
index 00000000000000..87f4711146ce9a
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/secure-iframe-in-insecure-context.html
@@ -0,0 +1,32 @@
+<!DOCTYPE html>
+<html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<script src="resources/observe-entry.js"></script>
+
+<body>
+</body>
+<script>
+  const { HTTPS_ORIGIN } = get_host_info();
+
+  promise_test(async t => {
+    const iframe = document.createElement('iframe');
+    iframe.src = `${HTTPS_ORIGIN}/resource-timing/resources/200.https.asis?1`;
+    document.body.appendChild(iframe);
+    t.add_cleanup(() => iframe.remove());
+    const entry = await observe_entry(iframe.src);
+    assert_not_equals(entry.secureConnectionStart, 0);
+  }, 'secureConnectionStart is reported for iframes loaded over https in http context');
+
+  promise_test(async t => {
+    const object = document.createElement('object');
+    object.data = `${HTTPS_ORIGIN}/resource-timing/resources/200.https.asis?2`;
+    document.body.appendChild(object);
+    t.add_cleanup(() => object.remove());
+    const entry = await observe_entry(object.data);
+    assert_not_equals(entry.secureConnectionStart, 0);
+  }, 'secureConnectionStart is reported for object documents loaded over https in http context');
+</script>
+
+</html>
diff --git a/test/fixtures/wpt/resource-timing/shared-worker-rt-entry.html b/test/fixtures/wpt/resource-timing/shared-worker-rt-entry.html
new file mode 100644
index 00000000000000..194500a09503a4
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/shared-worker-rt-entry.html
@@ -0,0 +1,26 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing Entry for Shared Workers</title>
+<link rel="help" href="https://w3c.github.io/resource-timing/"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/utils.js"></script>
+</head>
+<body>
+<script>
+    promise_test(async () => {
+        const url = new URL(`resources/shared-worker.js?${token()}`, location.href).toString();
+        const worker = new SharedWorker(url, 'name');
+        const {data} = await new Promise(resolve => {
+            worker.port.onmessage = resolve;
+        });
+
+        const timeOrigin = data;
+        const entries = performance.getEntriesByName(url);
+        assert_equals(entries.length, 0, "SharedWorker should not create a ResourceTiming entry");
+    }, "Shared workers should not generate Resource Timing Entries");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/sizes-cache.any.js b/test/fixtures/wpt/resource-timing/sizes-cache.any.js
new file mode 100644
index 00000000000000..af70e5a6ded3e6
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/sizes-cache.any.js
@@ -0,0 +1,55 @@
+// META: global=window,worker
+// META: script=/resource-timing/resources/sizes-helper.js
+// META: script=/resource-timing/resources/resource-loaders.js
+
+let url = new URL(
+  '/resource-timing/resources/cacheable-and-validated.py' +
+  '?content=loremipsumblablabla',
+  location.href).href;
+const bodySize = 19;
+
+const accumulateEntries = () => {
+  return new Promise(resolve => {
+    const po = new PerformanceObserver(list => {
+      resolve(list);
+    });
+    po.observe({type: "resource", buffered: true});
+  });
+};
+
+const checkResourceSizes = list => {
+  const entries = list.getEntriesByName(url);
+  assert_equals(entries.length, 3, 'Wrong number of entries');
+  let seenCount = 0;
+  for (let entry of entries) {
+    if (seenCount === 0) {
+      // 200 response
+      checkSizeFields(entry, bodySize, bodySize + headerSize);
+    } else if (seenCount === 1) {
+      // from cache
+      checkSizeFields(entry, bodySize, 0);
+    } else if (seenCount === 2) {
+      // 304 response
+      checkSizeFields(entry, bodySize, headerSize);
+    } else {
+      assert_unreached('Too many matching entries');
+    }
+    ++seenCount;
+  }
+};
+
+promise_test(() => {
+  // Use a different URL every time so that the cache behaviour does not
+  // depend on execution order.
+  url = load.cache_bust(url);
+  const eatBody = response => response.arrayBuffer();
+  const mustRevalidate = {headers: {'Cache-Control': 'max-age=0'}};
+  return fetch(url)
+    .then(eatBody)
+    .then(() => fetch(url))
+    .then(eatBody)
+    .then(() => fetch(url, mustRevalidate))
+    .then(eatBody)
+    .then(accumulateEntries)
+    .then(checkResourceSizes);
+}, 'PerformanceResourceTiming sizes caching test');
diff --git a/test/fixtures/wpt/resource-timing/sizes-redirect-img.html b/test/fixtures/wpt/resource-timing/sizes-redirect-img.html
new file mode 100644
index 00000000000000..786018d0c4634c
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/sizes-redirect-img.html
@@ -0,0 +1,57 @@
+<!DOCTYPE html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<script src="resources/sizes-helper.js"></script>
+<script src="resources/resource-loaders.js"></script>
+<script src="resources/entry-invariants.js"></script>
+<script>
+// Redirects for fetch() always apply CORS rules, whereas normal resources
+// don't, so this test covers extra code paths beyond those covered by
+// resource-timing-sizes-redirect.html.
+
+const baseUrl = new URL('/resource-timing/resources/TAOResponse.py?tao=wildcard&img=true', location.href).href;
+
+const expectedSize = 1010;
+
+const hostInfo = get_host_info();
+
+const redirectUrl = (redirectSourceOrigin, targetUrl) => {
+  return redirectSourceOrigin +
+    '/resource-timing/resources/redirect-cors.py?timing_allow_origin=*' +
+    '&location=' + encodeURIComponent(targetUrl);
+};
+
+const verify_entry = entry => {
+  checkSizeFields(entry, expectedSize, expectedSize + headerSize);
+};
+
+attribute_test(load.image, baseUrl,
+  verify_entry,
+  "PerformanceResourceTiming sizes redirect image - direct URL");
+
+attribute_test(load.image,
+  redirectUrl(hostInfo.HTTP_ORIGIN, baseUrl),
+  verify_entry,
+  "PerformanceResourceTiming sizes redirect image - same origin redirect");
+
+attribute_test(load.image,
+  redirectUrl(hostInfo.HTTP_REMOTE_ORIGIN, baseUrl),
+  verify_entry,
+  "PerformanceResourceTiming sizes redirect image - cross origin redirect");
+
+attribute_test(load.image,
+  redirectUrl(hostInfo.HTTP_REMOTE_ORIGIN,
+    redirectUrl(hostInfo.HTTP_ORIGIN, baseUrl)),
+  verify_entry,
+  "PerformanceResourceTiming sizes redirect image - cross origin to same origin redirect");
+
+attribute_test(load.image,
+  redirectUrl(hostInfo.HTTP_ORIGIN,
+    redirectUrl(hostInfo.HTTP_REMOTE_ORIGIN,
+      redirectUrl(hostInfo.HTTP_ORIGIN,
+        baseUrl))),
+  verify_entry,
+  "PerformanceResourceTiming sizes redirect image - same origin to remote " +
+  "origin to same origin redirect");
+</script>
diff --git a/test/fixtures/wpt/resource-timing/sizes-redirect.any.js b/test/fixtures/wpt/resource-timing/sizes-redirect.any.js
new file mode 100644
index 00000000000000..e483a4d409c6c2
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/sizes-redirect.any.js
@@ -0,0 +1,62 @@
+// META: global=window,worker
+// META: script=/common/get-host-info.sub.js
+// META: script=/resource-timing/resources/sizes-helper.js
+
+const baseUrl =
+  new URL('/resource-timing/resources/TAOResponse.py?tao=wildcard', location.href).href;
+const expectedSize = 4;
+
+const hostInfo = get_host_info();
+performance.clearResourceTimings();
+
+const accumulateEntry = () => {
+  return new Promise(resolve => {
+    const po = new PerformanceObserver(list => {
+      resolve(list);
+    });
+    po.observe({type: "resource", buffered: true});
+  });
+};
+
+const checkResourceSizes = () => {
+  const entries = performance.getEntriesByType('resource');
+  for (let entry of entries) {
+    checkSizeFields(entry, expectedSize, expectedSize + headerSize);
+  }
+}
+
+const redirectUrl = (redirectSourceOrigin, allowOrigin, targetUrl) => {
+  return redirectSourceOrigin +
+    '/resource-timing/resources/redirect-cors.py?allow_origin=' +
+    encodeURIComponent(allowOrigin) +
+    '&timing_allow_origin=*' +
+    '&location=' + encodeURIComponent(targetUrl);
+}
+
+promise_test(() => {
+  // Use a different URL every time so that the cache behaviour does not
+  // depend on execution order.
+  const directUrl = cacheBustUrl(baseUrl);
+  const sameOriginRedirect = redirectUrl(hostInfo.ORIGIN, '*', directUrl);
+  const crossOriginRedirect = redirectUrl(hostInfo.REMOTE_ORIGIN,
+    hostInfo.ORIGIN, directUrl);
+  const mixedRedirect = redirectUrl(hostInfo.REMOTE_ORIGIN,
+    hostInfo.ORIGIN, sameOriginRedirect);
+  const complexRedirect = redirectUrl(hostInfo.ORIGIN,
+    hostInfo.REMOTE_ORIGIN, mixedRedirect);
+  let eatBody = response => response.arrayBuffer();
+  return fetch(directUrl)
+    .then(eatBody)
+    .then(() => fetch(sameOriginRedirect))
+    .then(eatBody)
+    .then(() => fetch(crossOriginRedirect))
+    .then(eatBody)
+    .then(() => fetch(mixedRedirect))
+    .then(eatBody)
+    .then(() => fetch(complexRedirect))
+    .then(eatBody)
+    .then(accumulateEntry)
+    .then(checkResourceSizes);
+}, 'PerformanceResourceTiming sizes Fetch with redirect test');
+
+done();
diff --git a/test/fixtures/wpt/resource-timing/status-codes-create-entry.html b/test/fixtures/wpt/resource-timing/status-codes-create-entry.html
new file mode 100644
index 00000000000000..cc0cd8ccb88250
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/status-codes-create-entry.html
@@ -0,0 +1,40 @@
+<!doctype html>
+<html>
+<head>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<img src="resources/status-code.py?status=200">
+<img src="resources/status-code.py?status=307">
+<img src="resources/status-code.py?status=404">
+<img src="resources/status-code.py?status=502">
+<script src="resources/status-code.py?status=200&script=1"></script>
+<script src="resources/status-code.py?status=307&script=1"></script>
+<script src="resources/status-code.py?status=404&script=1"></script>
+<script src="resources/status-code.py?status=502&script=1"></script>
+<script>
+async_test(t => {
+  window.addEventListener("load", t.step_func_done(() => {
+    const images = document.getElementsByTagName("img");
+    for (let img of images) {
+      const entries = performance.getEntriesByName(img.src);
+      assert_greater_than(entries.length, 0, img.src);
+      assert_greater_than(entries[0].duration, 0, img.src);
+    }
+    const scripts = document.getElementsByTagName("script");
+    let noSrcScriptFound = false;
+    for (let script of scripts) {
+      if (script.src) {
+        const entries = performance.getEntriesByName(script.src);
+        assert_greater_than(entries.length, 0, script.src);
+        assert_greater_than(entries[0].duration, 0, script.src);
+      } else {
+        // Ignore this script, which has no src value. There should only be one such script.
+        assert_false(noSrcScriptFound);
+        noSrcScriptFound = true;
+      }
+    }
+  }));
+}, "Make sure all status codes are reported");
+</script>
diff --git a/test/fixtures/wpt/resource-timing/supported_resource_type.any.js b/test/fixtures/wpt/resource-timing/supported_resource_type.any.js
new file mode 100644
index 00000000000000..31e40096ddb2c3
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/supported_resource_type.any.js
@@ -0,0 +1,24 @@
+test(() => {
+  if (typeof PerformanceObserver.supportedEntryTypes === "undefined")
+    assert_unreached("supportedEntryTypes is not supported.");
+  assert_true(PerformanceObserver.supportedEntryTypes.includes("resource"),
+    "There should be an entry 'resource' in PerformanceObserver.supportedEntryTypes");
+}, "supportedEntryTypes contains 'resource'.");
+
+if (typeof PerformanceObserver.supportedEntryTypes !== "undefined") {
+  const entryType = "resource";
+  if (PerformanceObserver.supportedEntryTypes.includes(entryType)) {
+    promise_test(async() => {
+      await new Promise((resolve) => {
+        new PerformanceObserver(function (list, observer) {
+          observer.disconnect();
+          resolve();
+        }).observe({entryTypes: [entryType]});
+
+        // Force the PerformanceEntry.
+        // Use `self` for Workers.
+        fetch(self.location.href + "?" + Math.random());
+      })
+    }, `'${entryType}' entries should be observable.`)
+  }
+}
diff --git a/test/fixtures/wpt/resource-timing/test_resource_timing.html b/test/fixtures/wpt/resource-timing/test_resource_timing.html
new file mode 100644
index 00000000000000..f4e851abb203ac
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/test_resource_timing.html
@@ -0,0 +1,24 @@
+<!DOCTYPE html>
+<html>
+    <head>
+        <meta charset="UTF-8" />
+        <title>window.performance Resource Timing Entries exist</title>
+        <link rel="author" title="Microsoft" href="http://www.microsoft.com/" />
+        <link rel="help" href="https://w3c.github.io/web-performance/specs/ResourceTiming/Overview.html"/>
+        <script src="/resources/testharness.js"></script>
+        <script src="/resources/testharnessreport.js"></script>
+        <script src="test_resource_timing.js"></script>
+    </head>
+    <body>
+        <h1>Description</h1>
+        <p>
+           NOTE: Due to caching behavior in the browser, it is possible that when revisiting this page, some resources
+           may not have to be fetched from the network.  As a result, the performance timeline will not contain entries
+           for these resources. This test will fail if any entries are missing to ensure that all resources are fetched
+           from the network and entries for these resources exist in the Performance Timeline.  If revisiting this page,
+           please either perform a full reload of the page or clear the cache between visits.
+        </p>
+
+        <div id="log"></div>
+    </body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/test_resource_timing.https.html b/test/fixtures/wpt/resource-timing/test_resource_timing.https.html
new file mode 100644
index 00000000000000..f4e851abb203ac
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/test_resource_timing.https.html
@@ -0,0 +1,24 @@
+<!DOCTYPE html>
+<html>
+    <head>
+        <meta charset="UTF-8" />
+        <title>window.performance Resource Timing Entries exist</title>
+        <link rel="author" title="Microsoft" href="http://www.microsoft.com/" />
+        <link rel="help" href="https://w3c.github.io/web-performance/specs/ResourceTiming/Overview.html"/>
+        <script src="/resources/testharness.js"></script>
+        <script src="/resources/testharnessreport.js"></script>
+        <script src="test_resource_timing.js"></script>
+    </head>
+    <body>
+        <h1>Description</h1>
+        <p>
+           NOTE: Due to caching behavior in the browser, it is possible that when revisiting this page, some resources
+           may not have to be fetched from the network.  As a result, the performance timeline will not contain entries
+           for these resources. This test will fail if any entries are missing to ensure that all resources are fetched
+           from the network and entries for these resources exist in the Performance Timeline.  If revisiting this page,
+           please either perform a full reload of the page or clear the cache between visits.
+        </p>
+
+        <div id="log"></div>
+    </body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/test_resource_timing.js b/test/fixtures/wpt/resource-timing/test_resource_timing.js
new file mode 100644
index 00000000000000..598a727bf88e7f
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/test_resource_timing.js
@@ -0,0 +1,228 @@
+var TEST_ALLOWED_TIMING_DELTA = 20;
+
+var waitTimer;
+var expectedEntries = {};
+
+var initiatorTypes = ["iframe", "img", "link", "script", "xmlhttprequest"];
+
+var tests = {};
+setup(function() {
+    for (var i in initiatorTypes) {
+        var type = initiatorTypes[i];
+        tests[type] = {
+            "entry": async_test("window.performance.getEntriesByName() and window.performance.getEntriesByNameType() return same data (" + type + ")"),
+            "simple_attrs": async_test("PerformanceEntry has correct name, initiatorType, startTime, and duration (" + type + ")"),
+            "timing_attrs": async_test("PerformanceEntry has correct order of timing attributes (" + type + ")"),
+            "network_attrs": async_test("PerformanceEntry has correct network transfer attributes (" + type + ")"),
+            "protocol": async_test("PerformanceEntry has correct protocol attribute (" + type + ")")
+        };
+    }
+});
+
+function resolve(path) {
+    var a = document.createElement("a");
+    a.href = path;
+    return a.href;
+}
+
+onload = function()
+{
+    // check that the Performance Timeline API exists
+    test(function() {
+        assert_idl_attribute(window.performance, "getEntriesByName",
+                             "window.performance.getEntriesByName() is defined");
+    });
+    test(function() {
+        assert_idl_attribute(window.performance, "getEntriesByType",
+                             "window.performance.getEntriesByType() is defined");
+    });
+    test(function() {
+        assert_idl_attribute(window.performance, "getEntries",
+                             "window.performance.getEntries() is defined");
+    });
+
+    var expected_entry;
+    var url;
+    var type;
+    var startTime;
+    var element;
+    var encodedBodySize;
+    var decodedBodySize;
+    for (var i in initiatorTypes) {
+        startTime = window.performance.now();
+        type = initiatorTypes[i];
+        if (type != "xmlhttprequest") {
+            element = document.createElement(type);
+        } else {
+            element = null;
+        }
+        switch (type) {
+        case "iframe":
+            url = resolve("resources/resource_timing_test0.html");
+            element.src = url;
+            encodedBodySize = 215;
+            decodedBodySize = 215;
+            break;
+        case "img":
+            url = resolve("resources/resource_timing_test0.png");
+            element.src = url;
+            encodedBodySize = 249;
+            decodedBodySize = 249;
+            break;
+        case "link":
+            element.rel = "stylesheet";
+            url = resolve("resources/resource_timing_test0.css");
+            element.href = url;
+            encodedBodySize = 44;
+            decodedBodySize = 44;
+            break;
+        case "script":
+            element.type = "text/javascript";
+            url = resolve("resources/resource_timing_test0.js");
+            element.src = url;
+            encodedBodySize = 133;
+            decodedBodySize = 133;
+            break;
+        case "xmlhttprequest":
+            var xmlhttp = new XMLHttpRequest();
+            url = resolve("resources/gzip_xml.py");
+            xmlhttp.open('GET', url, true);
+            xmlhttp.send();
+            encodedBodySize = 112;
+            decodedBodySize = 125;
+            break;
+        }
+
+        expected_entry = {name:url,
+                          startTime: startTime,
+                          initiatorType: type,
+                          encodedBodySize: encodedBodySize,
+                          decodedBodySize: decodedBodySize
+                         };
+
+        switch (type) {
+        case "link":
+            poll_for_stylesheet_load(expected_entry);
+            document.body.appendChild(element);
+            break;
+        case "xmlhttprequest":
+            xmlhttp.onload = (function(entry) {
+                return function (event) {
+                    resource_load(entry);
+                };
+            })(expected_entry);
+            break;
+        default:
+            element.onload = (function(entry) {
+                return function (event) {
+                    resource_load(entry);
+                };
+            })(expected_entry);
+            document.body.appendChild(element);
+        }
+
+    }
+};
+
+function poll_for_stylesheet_load(expected_entry) {
+    var t = tests[expected_entry.initiatorType];
+
+    function inner() {
+        for(var i=0; i<document.styleSheets.length; i++) {
+            var sheet = document.styleSheets[i];
+            if (sheet.href === expected_entry.name) {
+                try {
+                    // try/catch avoids throwing if sheet object exists before it is loaded,
+                    // which is a bug, but not what we are trying to test here.
+                    var hasRules = sheet.cssRules.length > 0;
+                } catch(e) {
+                    hasRules = false;
+                }
+                if (hasRules) {
+                    t["entry"].step_timeout(function() {
+                        resource_load(expected_entry);
+                    }, 200);
+                    return;
+                }
+            }
+        }
+        t["entry"].step_timeout(inner, 100);
+    }
+    inner();
+}
+
+function resource_load(expected)
+{
+    var t = tests[expected.initiatorType];
+
+    t["entry"].step(function() {
+        var entries_by_name = window.performance.getEntriesByName(expected.name);
+        assert_equals(entries_by_name.length, 1, "should have a single entry for each resource (without type)");
+        var entries_by_name_type = window.performance.getEntriesByName(expected.name, "resource");
+        assert_equals(entries_by_name_type.length, 1, "should have a single entry for each resource (with type)");
+        assert_not_equals(entries_by_name, entries_by_name_type, "values should be copies");
+        for (p in entries_by_name[0]) {
+            var assertMethod = assert_equals
+            if (Array.isArray(entries_by_name[0][p]) && Array.isArray(entries_by_name_type[0][p])) {
+              assertMethod = assert_array_equals
+            }
+            assertMethod(entries_by_name[0][p], entries_by_name_type[0][p], "Property " + p + " should match");
+        }
+        this.done();
+    });
+
+    t["simple_attrs"].step(function() {
+        var actual = window.performance.getEntriesByName(expected.name)[0];
+        var expected_type = expected.initiatorType;
+        assert_equals(actual.name, expected.name);
+        assert_equals(actual.initiatorType, expected_type);
+        assert_equals(actual.entryType, "resource");
+        assert_greater_than_equal(actual.startTime, expected.startTime, "startTime is after the script to initiate the load ran");
+        assert_equals(actual.duration, (actual.responseEnd - actual.startTime));
+        this.done();
+    });
+
+    t["timing_attrs"].step(function test() {
+        const entries = window.performance.getEntriesByName(expected.name);
+        assert_equals(entries.length, 1, 'There should be a single matching entry');
+        const actual = entries[0];
+        if (window.location.protocol == "http:") {
+            assert_equals(actual.secureConnectionStart, 0, 'secureConnectionStart should be 0 in http');
+        } else {
+            assert_greater_than(actual.secureConnectionStart, 0, 'secureConnectionStart should not be 0 in https');
+        }
+
+        assert_equals(actual.redirectStart, 0, 'redirectStart should be 0');
+        assert_equals(actual.redirectEnd, 0, 'redirectEnd should be 0');
+        assert_equals(actual.fetchStart, actual.startTime, 'fetchStart is equal to startTime');
+        assert_greater_than_equal(actual.domainLookupStart, actual.fetchStart, 'domainLookupStart after fetchStart');
+        assert_greater_than_equal(actual.domainLookupEnd, actual.domainLookupStart, 'domainLookupEnd after domainLookupStart');
+        assert_greater_than_equal(actual.connectStart, actual.domainLookupEnd, 'connectStart after domainLookupEnd');
+        assert_greater_than_equal(actual.connectEnd, actual.connectStart, 'connectEnd after connectStart');
+        assert_true(actual.secureConnectionStart == 0 || actual.secureConnectionStart <= actual.requestStart,
+            "secureConnectionStart should be either 0 or smaller than/equals to requestStart")
+        assert_greater_than_equal(actual.requestStart, actual.connectEnd, 'requestStart after connectEnd');
+        assert_greater_than_equal(actual.responseStart, actual.requestStart, 'responseStart after requestStart');
+        assert_greater_than_equal(actual.responseEnd, actual.responseStart, 'responseEnd after responseStart');
+        this.done();
+    });
+
+    t["network_attrs"].step(function test() {
+        var actual = window.performance.getEntriesByName(expected.name)[0];
+        assert_equals(actual.encodedBodySize, expected.encodedBodySize, "encodedBodySize size");
+        assert_equals(actual.decodedBodySize, expected.decodedBodySize, "decodedBodySize size");
+
+        // Transfer size will vary from browser to browser based on default headers, etc. This
+        // test verifies that transferSize for uncached resources is greater than on-the-wire
+        // body size.
+        assert_greater_than(actual.transferSize, actual.encodedBodySize, "transferSize size");
+        this.done();
+    });
+
+    t["protocol"].step(function() {
+        var actual = window.performance.getEntriesByName(expected.name)[0];
+        assert_equals(actual.nextHopProtocol, "http/1.1", "expected protocol");
+        this.done();
+    });
+
+}
diff --git a/test/fixtures/wpt/resource-timing/tojson.html b/test/fixtures/wpt/resource-timing/tojson.html
new file mode 100644
index 00000000000000..7a6187d3d55bcd
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/tojson.html
@@ -0,0 +1,69 @@
+<!doctype html>
+<html>
+<head>
+<meta charset="utf-8">
+<title>This test validates that PerformanceResourceTiming's toJSON method
+       contains all of the entry's attributes.</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help"
+      href="https://www.w3.org/TR/resource-timing-2/#dom-performanceresourcetiming-tojson">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<script>
+promise_test(() => {
+  return new Promise((resolve, reject) => {
+    const po = new PerformanceObserver(list => {
+      const entries = list.getEntries();
+      if (entries.length < 1) {
+        throw new Error(`No entries to run the test with.`);
+      }
+      assert_greater_than_equal(entries.length, 1);
+      const entry = entries[0];
+      assert_equals(typeof(entry.toJSON), 'function');
+      const json = entry.toJSON();
+      assert_equals(typeof(json), 'object');
+
+      const performanceResourceTimingKeys = [
+        'name',
+        'entryType',
+        'startTime',
+        'duration',
+        'initiatorType',
+        'nextHopProtocol',
+        'workerStart',
+        'redirectStart',
+        'redirectEnd',
+        'fetchStart',
+        'domainLookupStart',
+        'domainLookupEnd',
+        'connectStart',
+        'connectEnd',
+        'secureConnectionStart',
+        'requestStart',
+        'responseStart',
+        'responseEnd',
+        'transferSize',
+        'encodedBodySize',
+        'decodedBodySize',
+        'renderBlockingStatus'
+      ];
+      for (const key of performanceResourceTimingKeys) {
+        try {
+          assert_false(json[key] === undefined,
+            `entry.toJSON().${key} is undefined`);
+          assert_equals(json[key], entry[key],
+            `entry.toJSON().${key} should match entry.${key}`);
+        } catch(e) {
+          reject(e);
+        }
+      }
+      resolve();
+    });
+    po.observe({type: "resource", buffered: true});
+  });
+}, 'Test toJSON() in PerformanceResourceTiming');
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/workerStart-tao-protected.https.html b/test/fixtures/wpt/resource-timing/workerStart-tao-protected.https.html
new file mode 100644
index 00000000000000..f54c0f2756eac3
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/workerStart-tao-protected.https.html
@@ -0,0 +1,76 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing - Check that workerStart is TAO protected</title>
+<link rel="author" title="Google" href="http://www.google.com/" />
+<link rel="help"
+  href="https://www.w3.org/TR/resource-timing-2/#sec-performanceresourcetiming">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<script src="resources/entry-invariants.js"></script>
+<script src="resources/resource-loaders.js"></script>
+</head>
+<body>
+<script>
+
+const {HTTPS_REMOTE_ORIGIN} = get_host_info();
+
+const worker_has_unregistered = new Promise(resolve => {
+  addEventListener("message", e => {
+    if (e.data === "unregistered") {
+      resolve();
+    }
+  });
+});
+
+// Open window to remote origin with a SW install.
+let openee;
+const service_worker_has_installed = new Promise(resolve => {
+  addEventListener("message", e => {
+    if (e.data === 'installed') {
+      resolve();
+    }
+  });
+  openee = window.open(HTTPS_REMOTE_ORIGIN +
+    "/resource-timing/resources/sw-install.html");
+});
+
+const load_after_sw_install = async path => {
+  await service_worker_has_installed;
+  return load.iframe(path);
+}
+
+attribute_test(load_after_sw_install,
+  `${HTTPS_REMOTE_ORIGIN}/resource-timing/resources/green.html`,
+  entry => {
+    assert_equals(entry.workerStart, 0, "workerStart must be zero");
+    invariants.assert_tao_failure_resource(entry);
+  },
+  "A resource from a cross-origin service worker must not expose workerStart " +
+  "when there is a TAO failure");
+
+attribute_test(load_after_sw_install,
+  `${HTTPS_REMOTE_ORIGIN}/resource-timing/resources/blank-with-tao.html`,
+  entry => {
+    assert_greater_than(entry.workerStart, 0,
+      "workerStart must be greater than zero");
+    // TODO(crbug.com/925239): need to add coverage for transferSize,
+    // encoded/decodedBodySize but that's broken right now.
+    // TODO(crbug.com/1171767): need to add coverage for SW-handled resources
+    // that redirect. Should workerStart be non-zero if any piece of the
+    // redirect chain is handled by a SW?
+  },
+  "A resource from a cross-origin service worker must expose workerStart " +
+  "when there is a TAO match");
+
+promise_test(async () => {
+  openee.postMessage("unregister", "*");
+  await worker_has_unregistered;
+  openee.close();
+}, "Not a test - needed to unregister the SW and close its embedder");
+
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/worklet-rt-entries.https.html b/test/fixtures/wpt/resource-timing/worklet-rt-entries.https.html
new file mode 100644
index 00000000000000..8ed280be1706b6
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/worklet-rt-entries.https.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing Entry Sequence of Events for Worklets</title>
+<link rel="help" href="https://w3c.github.io/resource-timing/"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<script>
+    promise_test(async() => {
+        const url = new URL("/worklets/resources/empty-worklet-script.js", location.href).toString();
+        await CSS.paintWorklet.addModule(url);
+        assert_equals(performance.getEntriesByName(url).length, 1);
+    }, "Worklets should generate Resource Timing Entries");
+</script>
+</body>
+</html>
diff --git a/test/fixtures/wpt/resource-timing/xhr-resource-timing.html b/test/fixtures/wpt/resource-timing/xhr-resource-timing.html
new file mode 100644
index 00000000000000..6f8f3331861062
--- /dev/null
+++ b/test/fixtures/wpt/resource-timing/xhr-resource-timing.html
@@ -0,0 +1,29 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>This test validates that a failed cross-origin fetch creates an opaque network timing entry.
+</title>
+<link rel="author" title="Noam Rosenthal" href="noam@webkit.org">
+<link rel="help" href="https://www.w3.org/TR/resource-timing-2/#sec-performanceresourcetiming"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/resource-loaders.js"></script>
+<script src="resources/entry-invariants.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+</head>
+<body>
+<script>
+const {REMOTE_ORIGIN} = get_host_info();
+
+attribute_test(
+  load.xhr_async, "/common/dummy.xml",
+  invariants.assert_tao_pass_no_redirect_http,
+  "Verify resource timing entry creation for successful XHR");
+
+attribute_test(
+  load.xhr_async, `${REMOTE_ORIGIN}/common/dummy.xml`,
+  invariants.assert_tao_failure_resource,
+    "Verify resource timing entry creation for XHR failing with CORS");
+</script>
+</body>
\ No newline at end of file
diff --git a/test/fixtures/wpt/versions.json b/test/fixtures/wpt/versions.json
index 3e223cd7d93b35..bda346e3ccf210 100644
--- a/test/fixtures/wpt/versions.json
+++ b/test/fixtures/wpt/versions.json
@@ -44,13 +44,17 @@
     "path": "html/webappapis/timers"
   },
   "interfaces": {
-    "commit": "fc086c82d5a7e9b01a684a23336d6d1f9e79e303",
+    "commit": "df731dab88a1a25c04eb7e6238c11dc28fda0801",
     "path": "interfaces"
   },
   "performance-timeline": {
     "commit": "17ebc3aea0d6321e69554067c39ab5855e6fb67e",
     "path": "performance-timeline"
   },
+  "resource-timing": {
+    "commit": "22d38586d04c1d22b64db36f439c6bb84f03db7d",
+    "path": "resource-timing"
+  },
   "resources": {
     "commit": "c5b428f15acfb17fe59b5a6f04a21c288a76ed36",
     "path": "resources"
diff --git a/test/parallel/test-perf-hooks-resourcetiming.js b/test/parallel/test-perf-hooks-resourcetiming.js
index 056924c4eb8c6f..889e1ad02af5ce 100644
--- a/test/parallel/test-perf-hooks-resourcetiming.js
+++ b/test/parallel/test-perf-hooks-resourcetiming.js
@@ -7,18 +7,15 @@ const {
   PerformanceObserver,
   PerformanceEntry,
   PerformanceResourceTiming,
-  performance: {
-    clearResourceTimings,
-    markResourceTiming,
-  },
+  performance,
 } = require('perf_hooks');
 
 assert(PerformanceObserver);
 assert(PerformanceEntry);
 assert.throws(() => new PerformanceEntry(), { code: 'ERR_ILLEGAL_CONSTRUCTOR' });
 assert(PerformanceResourceTiming);
-assert(clearResourceTimings);
-assert(markResourceTiming);
+assert(performance.clearResourceTimings);
+assert(performance.markResourceTiming);
 
 function createTimingInfo({
   startTime = 0,
@@ -78,7 +75,7 @@ function createTimingInfo({
   const requestedUrl = 'http://localhost:8080';
   const cacheMode = 'local';
   const initiatorType = 'fetch';
-  const resource = markResourceTiming(
+  const resource = performance.markResourceTiming(
     timingInfo,
     requestedUrl,
     initiatorType,
@@ -107,7 +104,7 @@ function createTimingInfo({
     assert(entries[0] instanceof PerformanceResourceTiming);
   }
 
-  clearResourceTimings();
+  performance.clearResourceTimings();
   assert.strictEqual(performance.getEntries().length, 0);
 }
 
@@ -120,7 +117,7 @@ function createTimingInfo({
   const requestedUrl = 'http://localhost:8080';
   const cacheMode = 'local';
   const initiatorType = 'fetch';
-  const resource = markResourceTiming(
+  const resource = performance.markResourceTiming(
     timingInfo,
     requestedUrl,
     initiatorType,
@@ -228,7 +225,7 @@ function createTimingInfo({
   assert(resource instanceof PerformanceEntry);
   assert(resource instanceof PerformanceResourceTiming);
 
-  clearResourceTimings();
+  performance.clearResourceTimings();
   const entries = performance.getEntries();
   assert.strictEqual(entries.length, 0);
 }
@@ -244,7 +241,7 @@ function createTimingInfo({
   const requestedUrl = 'http://localhost:8080';
   const cacheMode = '';
   const initiatorType = 'fetch';
-  const resource = markResourceTiming(
+  const resource = performance.markResourceTiming(
     timingInfo,
     requestedUrl,
     initiatorType,
@@ -267,7 +264,7 @@ function createTimingInfo({
   assert(resource instanceof PerformanceEntry);
   assert(resource instanceof PerformanceResourceTiming);
 
-  clearResourceTimings();
+  performance.clearResourceTimings();
   const entries = performance.getEntries();
   assert.strictEqual(entries.length, 0);
 }
@@ -299,7 +296,7 @@ function createTimingInfo({
   const requestedUrl = 'http://localhost:8080';
   const cacheMode = 'local';
   const initiatorType = 'fetch';
-  const resource = markResourceTiming(
+  const resource = performance.markResourceTiming(
     timingInfo,
     requestedUrl,
     initiatorType,
@@ -310,7 +307,7 @@ function createTimingInfo({
   assert(resource instanceof PerformanceEntry);
   assert(resource instanceof PerformanceResourceTiming);
 
-  clearResourceTimings();
+  performance.clearResourceTimings();
   const entries = performance.getEntries();
   assert.strictEqual(entries.length, 0);
 }
diff --git a/test/parallel/test-perf-hooks-usertiming.js b/test/parallel/test-perf-hooks-usertiming.js
index 71cc28c0f9c3a3..c6fd664fdce902 100644
--- a/test/parallel/test-perf-hooks-usertiming.js
+++ b/test/parallel/test-perf-hooks-usertiming.js
@@ -6,22 +6,20 @@ const {
   PerformanceObserver,
   PerformanceEntry,
   PerformanceMark,
+  performance,
   performance: {
     nodeTiming,
-    mark,
-    measure,
-    clearMarks,
   },
 } = require('perf_hooks');
 
 assert(PerformanceObserver);
 assert(PerformanceEntry);
 assert(PerformanceMark);
-assert(mark);
-assert(measure);
+assert(performance.mark);
+assert(performance.measure);
 
 [undefined, 'a', 'null', 1, true].forEach((i) => {
-  const m = mark(i);
+  const m = performance.mark(i);
   assert(m instanceof PerformanceEntry);
   assert(m instanceof PerformanceMark);
 
@@ -32,20 +30,20 @@ assert(measure);
   assert.strictEqual(m.detail, null);
 });
 
-clearMarks();
+performance.clearMarks();
 
-assert.throws(() => mark(Symbol('a')), {
+assert.throws(() => performance.mark(Symbol('a')), {
   message: /Cannot convert a Symbol value to a string/
 });
 
 [undefined, null].forEach((detail) => {
-  const m = mark('a', { detail });
+  const m = performance.mark('a', { detail });
   assert.strictEqual(m.name, 'a');
   assert.strictEqual(m.entryType, 'mark');
   assert.strictEqual(m.detail, null);
 });
 [1, 'any', {}, [], /a/].forEach((detail) => {
-  const m = mark('a', { detail });
+  const m = performance.mark('a', { detail });
   assert.strictEqual(m.name, 'a');
   assert.strictEqual(m.entryType, 'mark');
   // Value of detail is structured cloned.
@@ -55,31 +53,31 @@ assert.throws(() => mark(Symbol('a')), {
   }
 });
 
-clearMarks();
+performance.clearMarks();
 
 {
-  const m = mark('a', { startTime: 1 });
+  const m = performance.mark('a', { startTime: 1 });
   assert.strictEqual(m.startTime, 1);
 }
 
-assert.throws(() => mark('a', { startTime: 'a' }), {
+assert.throws(() => performance.mark('a', { startTime: 'a' }), {
   code: 'ERR_INVALID_ARG_TYPE'
 });
 
-clearMarks();
-clearMarks(1);
-clearMarks(null);
+performance.clearMarks();
+performance.clearMarks(1);
+performance.clearMarks(null);
 
-assert.throws(() => clearMarks(Symbol('foo')), {
+assert.throws(() => performance.clearMarks(Symbol('foo')), {
   message: /Cannot convert a Symbol value to a string/
 });
 
 {
-  mark('a', { startTime: 0 });
-  mark('b', { startTime: 10 });
+  performance.mark('a', { startTime: 0 });
+  performance.mark('b', { startTime: 10 });
 
   {
-    const m3 = measure('foo', 'a', 'b');
+    const m3 = performance.measure('foo', 'a', 'b');
     assert.strictEqual(m3.name, 'foo');
     assert.strictEqual(m3.entryType, 'measure');
     assert.strictEqual(m3.startTime, 0);
@@ -87,7 +85,7 @@ assert.throws(() => clearMarks(Symbol('foo')), {
   }
 
   {
-    const m3 = measure('foo', 'a');
+    const m3 = performance.measure('foo', 'a');
     assert.strictEqual(m3.name, 'foo');
     assert.strictEqual(m3.entryType, 'measure');
     assert.strictEqual(m3.startTime, 0);
@@ -95,7 +93,7 @@ assert.throws(() => clearMarks(Symbol('foo')), {
   }
 
   {
-    const m3 = measure('foo', { start: 'a' });
+    const m3 = performance.measure('foo', { start: 'a' });
     assert.strictEqual(m3.name, 'foo');
     assert.strictEqual(m3.entryType, 'measure');
     assert.strictEqual(m3.startTime, 0);
@@ -103,7 +101,7 @@ assert.throws(() => clearMarks(Symbol('foo')), {
   }
 
   {
-    const m3 = measure('foo', { end: 'b' });
+    const m3 = performance.measure('foo', { end: 'b' });
     assert.strictEqual(m3.name, 'foo');
     assert.strictEqual(m3.entryType, 'measure');
     assert.strictEqual(m3.startTime, 0);
@@ -111,7 +109,7 @@ assert.throws(() => clearMarks(Symbol('foo')), {
   }
 
   {
-    const m3 = measure('foo', { duration: 11, end: 'b' });
+    const m3 = performance.measure('foo', { duration: 11, end: 'b' });
     assert.strictEqual(m3.name, 'foo');
     assert.strictEqual(m3.entryType, 'measure');
     assert.strictEqual(m3.startTime, -1);
@@ -119,7 +117,7 @@ assert.throws(() => clearMarks(Symbol('foo')), {
   }
 
   {
-    const m3 = measure('foo', { duration: 11, start: 'b' });
+    const m3 = performance.measure('foo', { duration: 11, start: 'b' });
     assert.strictEqual(m3.name, 'foo');
     assert.strictEqual(m3.entryType, 'measure');
     assert.strictEqual(m3.startTime, 10);
@@ -127,7 +125,7 @@ assert.throws(() => clearMarks(Symbol('foo')), {
   }
 
   {
-    const m3 = measure('foo', 'nodeStart');
+    const m3 = performance.measure('foo', 'nodeStart');
     assert.strictEqual(m3.name, 'foo');
     assert.strictEqual(m3.entryType, 'measure');
     assert.strictEqual(m3.startTime, nodeTiming.nodeStart);
@@ -135,7 +133,7 @@ assert.throws(() => clearMarks(Symbol('foo')), {
   }
 
   {
-    const m3 = measure('foo', 'nodeStart', 'bootstrapComplete');
+    const m3 = performance.measure('foo', 'nodeStart', 'bootstrapComplete');
     assert.strictEqual(m3.name, 'foo');
     assert.strictEqual(m3.entryType, 'measure');
     assert.strictEqual(m3.startTime, nodeTiming.nodeStart);
@@ -145,14 +143,14 @@ assert.throws(() => clearMarks(Symbol('foo')), {
   }
 
   {
-    const m3 = measure('foo', { start: 'nodeStart', duration: 10 });
+    const m3 = performance.measure('foo', { start: 'nodeStart', duration: 10 });
     assert.strictEqual(m3.name, 'foo');
     assert.strictEqual(m3.entryType, 'measure');
     assert.strictEqual(m3.startTime, nodeTiming.nodeStart);
     assert.strictEqual(m3.duration, 10);
   }
 
-  clearMarks();
+  performance.clearMarks();
 }
 
 {
@@ -184,7 +182,7 @@ assert.throws(() => clearMarks(Symbol('foo')), {
     obs.disconnect();
   }));
   obs.observe({ entryTypes: ['mark', 'measure'] });
-  mark('a');
-  mark('b');
-  measure('a to b', 'a', 'b');
+  performance.mark('a');
+  performance.mark('b');
+  performance.measure('a to b', 'a', 'b');
 }
diff --git a/test/sequential/test-worker-eventlooputil.js b/test/sequential/test-worker-eventlooputil.js
index 7e012cb2b02e7a..55a3995c3d11c1 100644
--- a/test/sequential/test-worker-eventlooputil.js
+++ b/test/sequential/test-worker-eventlooputil.js
@@ -9,7 +9,8 @@ const {
   MessagePort,
   parentPort,
 } = require('worker_threads');
-const { eventLoopUtilization, now } = require('perf_hooks').performance;
+const { performance } = require('perf_hooks');
+const { eventLoopUtilization } = require('perf_hooks').performance;
 
 // Use argv to detect whether we're running as a Worker called by this test vs.
 // this test also being called as a Worker.
@@ -35,8 +36,8 @@ function workerOnMetricsMsg(msg) {
 
   if (msg.cmd === 'spin') {
     const elu = eventLoopUtilization();
-    const t = now();
-    while (now() - t < msg.dur);
+    const t = performance.now();
+    while (performance.now() - t < msg.dur);
     return this.postMessage(eventLoopUtilization(elu));
   }
 }
diff --git a/test/wpt/status/hr-time.json b/test/wpt/status/hr-time.json
index b23a5a4e96a6a4..973e32b298a557 100644
--- a/test/wpt/status/hr-time.json
+++ b/test/wpt/status/hr-time.json
@@ -1,7 +1,4 @@
 {
-  "idlharness.any.js": {
-    "skip": "TODO: update IDL parser"
-  },
   "window-worker-timeOrigin.window.js": {
     "skip": "depends on URL.createObjectURL(blob)"
   }
diff --git a/test/wpt/status/performance-timeline.json b/test/wpt/status/performance-timeline.json
index 207f2287746e96..9a297e641437df 100644
--- a/test/wpt/status/performance-timeline.json
+++ b/test/wpt/status/performance-timeline.json
@@ -1,16 +1,12 @@
 {
   "case-sensitivity.any.js": {
     "fail": {
-      "note": "resource entry type not supported",
+      "note": "self.location is not available",
       "expected": [
-        "getEntriesByType values are case sensitive",
         "getEntriesByName values are case sensitive"
       ]
     }
   },
-  "idlharness.any.js": {
-    "skip": "idlharness cannot recognize Node.js environment"
-  },
   "webtiming-resolution.any.js": {
     "skip": "flaky"
   }
diff --git a/test/wpt/status/resource-timing.json b/test/wpt/status/resource-timing.json
new file mode 100644
index 00000000000000..22f21cfe48d7fe
--- /dev/null
+++ b/test/wpt/status/resource-timing.json
@@ -0,0 +1,23 @@
+{
+  "cors-preflight.any.js": {
+    "skip": "Browser-specific test"
+  },
+  "resource_nested_dedicated_worker.worker.js": {
+    "skip": "Browser-specific test"
+  },
+  "resource_timing.worker.js": {
+    "skip": "Browser-specific test"
+  },
+  "sizes-cache.any.js": {
+    "skip": "Browser-specific test"
+  },
+  "sizes-redirect.any.js": {
+    "skip": "Browser-specific test"
+  },
+  "supported_resource_type.any.js": {
+    "skip": "Browser-specific test"
+  },
+  "buffered-flag.any.js": {
+    "skip": "Browser-specific test"
+  }
+}
diff --git a/test/wpt/status/user-timing.json b/test/wpt/status/user-timing.json
index b1110e6a5e798d..6e2b6e276ccda0 100644
--- a/test/wpt/status/user-timing.json
+++ b/test/wpt/status/user-timing.json
@@ -4,8 +4,5 @@
   },
   "performance-measure-invalid.worker.js": {
     "skip": "importScripts not supported"
-  },
-  "idlharness.any.js": {
-    "skip": "idlharness cannot recognize Node.js environment"
   }
 }
diff --git a/test/wpt/test-hr-time.js b/test/wpt/test-hr-time.js
index 36fdde8036c0cc..8900e8617bbc1d 100644
--- a/test/wpt/test-hr-time.js
+++ b/test/wpt/test-hr-time.js
@@ -5,12 +5,7 @@ const { WPTRunner } = require('../common/wpt');
 
 const runner = new WPTRunner('hr-time');
 
-runner.setInitScript(`
-  const { Blob } = require('buffer');
-  global.Blob = Blob;
-
-  const { PerformanceObserver } = require('perf_hooks');
-  global.PerformanceObserver = PerformanceObserver;
-`);
+runner.pretendGlobalThisAs('Window');
+runner.brandCheckGlobalScopeAttribute('performance');
 
 runner.runJsTests();
diff --git a/test/wpt/test-performance-timeline.js b/test/wpt/test-performance-timeline.js
index 12f1abd3a52a32..fb6e35155fcd8c 100644
--- a/test/wpt/test-performance-timeline.js
+++ b/test/wpt/test-performance-timeline.js
@@ -4,26 +4,56 @@ const { WPTRunner } = require('../common/wpt');
 
 const runner = new WPTRunner('performance-timeline');
 
-// Needed to access to DOMException.
-runner.setFlags(['--expose-internals']);
-
+runner.pretendGlobalThisAs('Window');
+runner.brandCheckGlobalScopeAttribute('performance');
 runner.setInitScript(`
   const {
-    PerformanceMark,
-    PerformanceMeasure,
+    PerformanceEntry,
     PerformanceObserver,
     PerformanceObserverEntryList,
-    performance,
   } = require('perf_hooks');
-  global.PerformanceMark = performance;
-  global.PerformanceMeasure = performance;
-  global.PerformanceObserver = PerformanceObserver;
-  global.PerformanceObserverEntryList = PerformanceObserverEntryList;
-  global.performance = performance;
+  Object.defineProperty(global, 'PerformanceEntry', {
+    value: PerformanceEntry,
+    enumerable: false,
+    writable: true,
+    configurable: true,
+  });
+  Object.defineProperty(global, 'PerformanceObserver', {
+    value: PerformanceObserver,
+    enumerable: false,
+    writable: true,
+    configurable: true,
+  });
+  Object.defineProperty(global, 'PerformanceObserverEntryList', {
+    value: PerformanceObserverEntryList,
+    enumerable: false,
+    writable: true,
+    configurable: true,
+  });
 
-  const { internalBinding } = require('internal/test/binding');
-  const { DOMException } = internalBinding('messaging');
-  global.DOMException = DOMException;
+  // Create a dummy resource timing entry to mimic how the browser would
+  // record the initial page load.
+  performance.markResourceTiming({
+    startTime: 0,
+    endTime: 0,
+    finalServiceWorkerStartTime: 0,
+    redirectStartTime: 0,
+    redirectEndTime: 0,
+    postRedirectStartTime: 0,
+    finalConnectionTimingInfo: {
+      domainLookupStartTime: 0,
+      domainLookupEndTime: 0,
+      connectionStartTime: 0,
+      connectionEndTime: 0,
+      secureConnectionStartTime: 0,
+      ALPNNegotiatedProtocol: '',
+    },
+    finalNetworkRequestStartTime: 0,
+    finalNetworkResponseStartTime: 0,
+    encodedBodySize: 0,
+    decodedBodySize: 0,
+  }, 'https://nodejs.org', '', global, '');
 `);
 
+
 runner.runJsTests();
diff --git a/test/wpt/test-resource-timing.js b/test/wpt/test-resource-timing.js
new file mode 100644
index 00000000000000..ea383f73b6d881
--- /dev/null
+++ b/test/wpt/test-resource-timing.js
@@ -0,0 +1,48 @@
+'use strict';
+require('../common');
+const { WPTRunner } = require('../common/wpt');
+
+const runner = new WPTRunner('resource-timing');
+
+runner.pretendGlobalThisAs('Window');
+runner.setInitScript(`
+  const {
+    PerformanceEntry,
+    PerformanceResourceTiming,
+  } = require('perf_hooks');
+  Object.defineProperty(global, 'PerformanceEntry', {
+    value: PerformanceEntry,
+    enumerable: false,
+    writable: true,
+    configurable: true,
+  });
+  Object.defineProperty(global, 'PerformanceResourceTiming', {
+    value: PerformanceResourceTiming,
+    enumerable: false,
+    writable: true,
+    configurable: true,
+  });
+
+  global.resource = performance.markResourceTiming({
+    startTime: 0,
+    endTime: 0,
+    finalServiceWorkerStartTime: 0,
+    redirectStartTime: 0,
+    redirectEndTime: 0,
+    postRedirectStartTime: 0,
+    finalConnectionTimingInfo: {
+      domainLookupStartTime: 0,
+      domainLookupEndTime: 0,
+      connectionStartTime: 0,
+      connectionEndTime: 0,
+      secureConnectionStartTime: 0,
+      ALPNNegotiatedProtocol: '',
+    },
+    finalNetworkRequestStartTime: 0,
+    finalNetworkResponseStartTime: 0,
+    encodedBodySize: 0,
+    decodedBodySize: 0,
+  }, 'https://nodejs.org', '', global, '');
+`);
+
+runner.runJsTests();
diff --git a/test/wpt/test-user-timing.js b/test/wpt/test-user-timing.js
index 36d13297ba57cc..f82d2411c3ece2 100644
--- a/test/wpt/test-user-timing.js
+++ b/test/wpt/test-user-timing.js
@@ -1,27 +1,43 @@
 'use strict';
+
 require('../common');
 const { WPTRunner } = require('../common/wpt');
 
 const runner = new WPTRunner('user-timing');
 
-// Needed to access to DOMException.
-runner.setFlags(['--expose-internals']);
-
+runner.pretendGlobalThisAs('Window');
+runner.brandCheckGlobalScopeAttribute('performance');
 runner.setInitScript(`
   const {
+    PerformanceEntry,
     PerformanceMark,
     PerformanceMeasure,
     PerformanceObserver,
-    performance,
   } = require('perf_hooks');
-  global.PerformanceMark = performance;
-  global.PerformanceMeasure = performance;
-  global.PerformanceObserver = PerformanceObserver;
-  global.performance = performance;
-
-  const { internalBinding } = require('internal/test/binding');
-  const { DOMException } = internalBinding('messaging');
-  global.DOMException = DOMException;
+  Object.defineProperty(global, 'PerformanceEntry', {
+    value: PerformanceEntry,
+    enumerable: false,
+    writable: true,
+    configurable: true,
+  });
+  Object.defineProperty(global, 'PerformanceMark', {
+    value: PerformanceMark,
+    enumerable: false,
+    writable: true,
+    configurable: true,
+  });
+  Object.defineProperty(global, 'PerformanceMeasure', {
+    value: PerformanceMeasure,
+    enumerable: false,
+    writable: true,
+    configurable: true,
+  });
+  Object.defineProperty(global, 'PerformanceObserver', {
+    value: PerformanceObserver,
+    enumerable: false,
+    writable: true,
+    configurable: true,
+  });
 `);
 
 runner.runJsTests();