From 5788df29aaafb4608874ba708dd56b444dc1b328 Mon Sep 17 00:00:00 2001
From: Kevin Schaaf <kschaaf@google.com>
Date: Wed, 27 Feb 2019 15:09:56 -0800
Subject: [PATCH] Revert "Use set and clear debouncer upon completion. Fixes
 #5250"

This reverts commit e8d2314476a3ddcd804ca5afe5881f6f717736d2.
---
 lib/utils/debounce.html | 32 ----------------------------
 lib/utils/flush.html    | 30 ++++++++++++++++++++++++--
 test/unit/debounce.html | 47 -----------------------------------------
 3 files changed, 28 insertions(+), 81 deletions(-)

diff --git a/lib/utils/debounce.html b/lib/utils/debounce.html
index 48efe629a5..1507faa20a 100644
--- a/lib/utils/debounce.html
+++ b/lib/utils/debounce.html
@@ -40,7 +40,6 @@
       this._timer = this._asyncModule.run(() => {
         this._timer = null;
         this._callback();
-        debouncerQueue.delete(this);
       });
     }
     /**
@@ -116,36 +115,5 @@
 
   /** @const */
   Polymer.Debouncer = Debouncer;
-
-  let debouncerQueue = new Set();
-  
-  /**
-   * Adds a `Debouncer` to a list of globally flushable tasks.
-   *
-   * @param {!Debouncer} debouncer Debouncer to enqueue
-   * @return {void}
-   */
-  Polymer.enqueueDebouncer = function(debouncer) {
-    if (debouncerQueue.has(debouncer)) {
-      debouncerQueue.delete(debouncer);
-    }
-    debouncerQueue.add(debouncer);
-  };
-  
-  Polymer.flushDebouncers = function() {
-    const didFlush = Boolean(debouncerQueue.size);
-    debouncerQueue.forEach(debouncer => {
-      try {
-        debouncer.flush();
-      } catch(e) {
-        setTimeout(() => {
-          throw e;
-        });
-      }
-    });
-    debouncerQueue = new Set();
-    return didFlush;
-  };
-
 })();
 </script>
diff --git a/lib/utils/flush.html b/lib/utils/flush.html
index 0ab98780cd..3feaad6166 100644
--- a/lib/utils/flush.html
+++ b/lib/utils/flush.html
@@ -8,11 +8,37 @@
 subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
 -->
 <link rel="import" href="boot.html">
-<link rel="import" href="debounce.html">
 <script>
 (function() {
   'use strict';
 
+  let debouncerQueue = [];
+
+  /**
+   * Adds a `Polymer.Debouncer` to a list of globally flushable tasks.
+   *
+   * @memberof Polymer
+   * @param {!Polymer.Debouncer} debouncer Debouncer to enqueue
+   * @return {void}
+   */
+  Polymer.enqueueDebouncer = function(debouncer) {
+    debouncerQueue.push(debouncer);
+  };
+
+  function flushDebouncers() {
+    const didFlush = Boolean(debouncerQueue.length);
+    while (debouncerQueue.length) {
+      try {
+        debouncerQueue.shift().flush();
+      } catch(e) {
+        setTimeout(() => {
+          throw e;
+        });
+      }
+    }
+    return didFlush;
+  }
+
   /**
    * Forces several classes of asynchronously queued tasks to flush:
    * - Debouncers added via `enqueueDebouncer`
@@ -28,7 +54,7 @@
       if (window.ShadyCSS && window.ShadyCSS.ScopingShim) {
         window.ShadyCSS.ScopingShim.flush();
       }
-      debouncers = Polymer.flushDebouncers();
+      debouncers = flushDebouncers();
     } while (shadyDOM || debouncers);
   };
 
diff --git a/test/unit/debounce.html b/test/unit/debounce.html
index 1c6e1520e5..96819d44a8 100644
--- a/test/unit/debounce.html
+++ b/test/unit/debounce.html
@@ -209,53 +209,6 @@
 
     });
   });
-
-  suite('enqueueDebouncer & flush', function() {
-    function testEnqueue(shouldFlush, done) {
-      // Longer-running debouncer
-      const timeoutCallback = sinon.spy(() => actualCallbacks.push(timeoutCallback));
-      Polymer.enqueueDebouncer(Polymer.Debouncer.debounce(null, Polymer.Async.timeOut, timeoutCallback));
-      // Set of short-running debouncers enqueued in the middle of first set
-      const nestedCallbacks = new Array(150).fill().map((_, i) => sinon.spy(() =>
-        actualCallbacks.push(nestedCallbacks[i])));
-      // First set of short-running debouncers
-      const microtaskCallbacks = new Array(150).fill().map((_, i) => sinon.spy(() => {
-        actualCallbacks.push(microtaskCallbacks[i]);
-        if (i === 125) {
-          nestedCallbacks.forEach(cb => 
-            Polymer.enqueueDebouncer(Polymer.Debouncer.debounce(null, Polymer.Async.microTask, cb)));
-        }
-      }));
-      microtaskCallbacks.forEach(cb => 
-        Polymer.enqueueDebouncer(Polymer.Debouncer.debounce(null, Polymer.Async.microTask, cb)));
-      // Expect short before long
-      let expectedCallbacks;
-      const actualCallbacks = [];
-      const verify = () => {
-        actualCallbacks.forEach(cb => assert.isTrue(cb.calledOnce));
-        assert.deepEqual(expectedCallbacks, actualCallbacks);
-        done();
-      };
-      if (shouldFlush) {
-        expectedCallbacks = [timeoutCallback, ...microtaskCallbacks, ...nestedCallbacks];
-        Polymer.flush();
-        // When flushing, order is order of enqueing
-        verify();
-      } else {
-        expectedCallbacks = [...microtaskCallbacks, ...nestedCallbacks, timeoutCallback];
-        Polymer.Async.timeOut.run(verify);
-      }
-    }
-
-    test('non-flushed', function(done) {
-      testEnqueue(false, done);
-    });
-
-    test('flushed', function(done) {
-      testEnqueue(true, done);
-    });
-
-  });
 </script>
 </body>
 </html>