Implement new AnimationTimeline superclass

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

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 69 matching lines @@
     compositor_timeline_ = CompositorAnimationTimeline::Create();
 
   DCHECK(document);
 }
 
 bool AnimationTimeline::IsActive() {
   return document_ && document_->GetPage();
 }
 
 void AnimationTimeline::AnimationAttached(Animation& animation) {
-  DCHECK_EQ(animation.timeline(), this);
+  DCHECK_EQ(animation.TimelineInternal(), this);
   DCHECK(!animations_.Contains(&animation));
   animations_.insert(&animation);
 }
 
 Animation* AnimationTimeline::Play(AnimationEffectReadOnly* child) {
   if (!document_)
     return nullptr;
 
   Animation* animation = Animation::Create(child, this);
   DCHECK(animations_.Contains(animation));
@@ skipping 214 matching lines @@
 void AnimationTimeline::InvalidateKeyframeEffects(const TreeScope& tree_scope) {
   for (const auto& animation : animations_)
     animation->InvalidateKeyframeEffect(tree_scope);
 }
 
 DEFINE_TRACE(AnimationTimeline) {
   visitor->Trace(document_);
   visitor->Trace(timing_);
   visitor->Trace(animations_needing_update_);
   visitor->Trace(animations_);
+  SuperAnimationTimeline::Trace(visitor);
 }
 
 }  // namespace blink