Web Animations: Fix bug with Document::getAnimations

Per spec, we should exclude effects that do not target an element in
the called document:

https://drafts.csswg.org/web-animations-1/#dom-document-getanimations

Bug: 828424
Change-Id: I41405d82184b17c1185931e34735a5f946573844
Reviewed-on: https://chromium-review.googlesource.com/992812
Commit-Queue: Stephen McGruer <smcgruer@chromium.org>
Reviewed-by: Xida Chen <xidachen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#548156}

third_party/WebKit/LayoutTests/external/wpt/web-animations/interfaces/Document/getAnimations-expected.txt

-This is a testharness.js-based test.
-PASS Test document.getAnimations for non-animated content
-PASS Test document.getAnimations for script-generated animations
-PASS Test the order of document.getAnimations with script generated animations
-FAIL Test document.getAnimations with null target assert_equals: document.getAnimations() only returns animations targeting elements in this document expected 0 but got 3
-Harness: the test ran to completion.
-

third_party/WebKit/LayoutTests/external/wpt/web-animations/interfaces/Document/getAnimations.html

@@ -41,6 +41,19 @@ test(t => {
                       'getAnimations() returns running animations');
 }, 'Test the order of document.getAnimations with script generated animations')
 
+test(t => {
+  // This element exists but is not a descendent of any document, so isn't
+  // picked up by getAnimations.
+  const div = document.createElement('div');
+  const anim = div.animate(gKeyFrames, 100 * MS_PER_SEC);
+  assert_equals(document.getAnimations().length, 0);
+
+  // Now connect the div; it should appear in the list of animations.
+  document.body.appendChild(div);
+  t.add_cleanup(() => { div.remove(); });
+  assert_equals(document.getAnimations().length, 1);
+}, 'Test document.getAnimations for a disconnected node');
+
 test(t => {
   const effect = new KeyframeEffect(null, gKeyFrames, 100 * MS_PER_SEC);
   const anim = new Animation(effect, document.timeline);

third_party/WebKit/Source/core/animation/DocumentTimeline.cpp

@@ -117,12 +117,24 @@ Animation* DocumentTimeline::Play(AnimationEffect* child) {
 }
 
 HeapVector<Member<Animation>> DocumentTimeline::getAnimations() {
+  // This method implements the Document::getAnimations method defined in the
+  // web-animations-1 spec.
+  // https://drafts.csswg.org/web-animations-1/#dom-document-getanimations
   document_->UpdateStyleAndLayoutTree();
   HeapVector<Member<Animation>> animations;
   for (const auto& animation : animations_) {
-    if (animation->effect() &&
-        (animation->effect()->IsCurrent() || animation->effect()->IsInEffect()))
-      animations.push_back(animation);
+    if (!animation->effect() || (!animation->effect()->IsCurrent() &&
+                                 !animation->effect()->IsInEffect())) {
+      continue;
+    }
+    if (animation->effect()->IsKeyframeEffect()) {
+      Element* target = ToKeyframeEffect(animation->effect())->target();
+      if (!target || !target->isConnected() ||
+          document_ != target->GetDocument()) {
+        continue;
+      }
+    }
+    animations.push_back(animation);
   }
   std::sort(animations.begin(), animations.end(), CompareAnimations);
   return animations;