createHTMLDocument() should not leave body in parsing state

[annevk]

dd8dcc1

createHTMLDocument() should not leave body in parsing state
https://bugs.webkit.org/show_bug.cgi?id=315847

Reviewed by Ryosuke Niwa.

createHTMLDocument() used to populate the document with a write() call
without a corresponding close() call. This meant that IsParsingChildren
did not get unset, impacting :last-child and friends. A subtest of
shadow-dom/untriaged/shadow-trees/upper-boundary-encapsulation/test-009.html
caught this.

So we re-implement createHTMLDocument() the way the specification
requires. This also impacts readyState (it's now "complete" instead of
"loading") and we take this opportunity to upstream the local tests.

Upstream: web-platform-tests/wpt#60293
Canonical link: https://commits.webkit.org/314295@main

7cbd314

Misc	iOS, visionOS, tvOS & watchOS	macOS	Linux	Windows	Apple Internal
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 win	⏳ 🛠 ios-apple
🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2	✅ 🧪 win-tests	⏳ 🛠 mac-apple
✅ 🧪 webkitperl	❌ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 api-wpe		⏳ 🛠 vision-apple
	❌ 🧪 ios-wk2-wpt	✅ 🧪 api-mac-debug	✅ 🛠 gtk3-libwebrtc
	✅ 🧪 api-ios	✅ 🧪 mac-wk1	✅ 🛠 gtk
	✅ 🛠 ios-safer-cpp	✅ 🧪 mac-wk2	✅ 🧪 gtk-wk2
	✅ 🛠 vision	✅ 🧪 mac-AS-debug-wk2	✅ 🧪 api-gtk
	✅ 🛠 vision-sim	✅ 🧪 mac-wk2-stress	✅ 🛠 playstation
✅ 🛠 🧪 unsafe-merge	✅ 🧪 vision-wk2	✅ 🧪 mac-intel-wk2
	✅ 🛠 tv	✅ 🛠 mac-safer-cpp
	✅ 🛠 tv-sim	✅ 🧪 mac-site-isolation
	✅ 🛠 watch
	✅ 🛠 watch-sim

[webkit-early-warning-system]

EWS run on previous version of this PR (hash cacee3d)

Details

Misc	iOS, visionOS, tvOS & watchOS	macOS	Linux	Windows	Apple Internal
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 win	🛠 ios-apple
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	❌ 🧪 wpe-wk2	🧪 win-tests	🛠 mac-apple
🧪 webkitperl	❌ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 api-wpe		🛠 vision-apple
🧪 webkitpy	✅ 🧪 ios-wk2-wpt	✅ 🧪 api-mac-debug	✅ 🛠 gtk3-libwebrtc
	✅ 🧪 api-ios	✅ 🧪 mac-wk1	✅ 🛠 gtk
	✅ 🛠 ios-safer-cpp	❌ 🧪 mac-wk2	❌ 🧪 gtk-wk2
	✅ 🛠 vision	❌ 🧪 mac-AS-debug-wk2	✅ 🧪 api-gtk
	✅ 🛠 vision-sim	✅ 🧪 mac-wk2-stress	✅ 🛠 playstation
	✅ 🧪 vision-wk2	❌ 🧪 mac-intel-wk2
	✅ 🛠 tv	✅ 🛠 mac-safer-cpp
	✅ 🛠 tv-sim	❌ 🧪 mac-site-isolation
	✅ 🛠 watch
	✅ 🛠 watch-sim

[webkit-early-warning-system]

EWS run on current version of this PR (hash 7cbd314)

Details

Misc	iOS, visionOS, tvOS & watchOS	macOS	Linux	Windows	Apple Internal
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 win	⏳ 🛠 ios-apple
🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2	✅ 🧪 win-tests	⏳ 🛠 mac-apple
✅ 🧪 webkitperl	❌ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 api-wpe		⏳ 🛠 vision-apple
	❌ 🧪 ios-wk2-wpt	✅ 🧪 api-mac-debug	✅ 🛠 gtk3-libwebrtc
	✅ 🧪 api-ios	✅ 🧪 mac-wk1	✅ 🛠 gtk
	✅ 🛠 ios-safer-cpp	✅ 🧪 mac-wk2	✅ 🧪 gtk-wk2
	✅ 🛠 vision	✅ 🧪 mac-AS-debug-wk2	✅ 🧪 api-gtk
	✅ 🛠 vision-sim	✅ 🧪 mac-wk2-stress	✅ 🛠 playstation
✅ 🛠 🧪 unsafe-merge	✅ 🧪 vision-wk2	✅ 🧪 mac-intel-wk2
	✅ 🛠 tv	✅ 🛠 mac-safer-cpp
	✅ 🛠 tv-sim	✅ 🧪 mac-site-isolation
	✅ 🛠 watch
	✅ 🛠 watch-sim

[webkit-commit-queue]

Committed 314295@main (dd8dcc1): https://commits.webkit.org/314295@main

Reviewed commits have been landed. Closing PR #66024 and removing active labels.