ElementAnimations should hold an ObservableList of AnimationPlayers.

cc/animation/animation_player.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_ANIMATION_ANIMATION_PLAYER_H_
 #define CC_ANIMATION_ANIMATION_PLAYER_H_
 
 #include <vector>
 
-#include "base/containers/linked_list.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/time/time.h"
 #include "cc/animation/animation.h"
 #include "cc/animation/animation_curve.h"
 #include "cc/animation/element_animations.h"
 #include "cc/base/cc_export.h"
 
 namespace cc {
 
 class AnimationDelegate;
 class AnimationHost;
 class AnimationTimeline;
 class ElementAnimations;
 
 // An AnimationPlayer owns all animations to be run on particular CC Layer.
 // Multiple AnimationPlayers can be attached to one layer. In this case,
 // they share common ElementAnimations so the
 // ElementAnimations-to-Layer relationship is 1:1.
 // For now, the blink logic is responsible for handling of conflicting
 // same-property animations.
 // Each AnimationPlayer has its copy on the impl thread.
 // This is a CC counterpart for blink::AnimationPlayer (in 1:1 relationship).
-class CC_EXPORT AnimationPlayer : public base::RefCounted<AnimationPlayer>,
-                                  public base::LinkNode<AnimationPlayer> {
+class CC_EXPORT AnimationPlayer : public base::RefCounted<AnimationPlayer> {
  public:
   static scoped_refptr<AnimationPlayer> Create(int id);
   scoped_refptr<AnimationPlayer> CreateImplInstance() const;
 
   int id() const { return id_; }
   ElementId element_id() const { return element_id_; }
 
   // Parent AnimationHost. AnimationPlayer can be detached from
   // AnimationTimeline.
   AnimationHost* animation_host() { return animation_host_; }
@@ skipping 75 matching lines @@
 
   int id_;
   ElementId element_id_;
 
   DISALLOW_COPY_AND_ASSIGN(AnimationPlayer);
 };
 
 }  // namespace cc
 
 #endif  // CC_ANIMATION_ANIMATION_PLAYER_H_