NOT FOR REVIEW - convert to cc animation

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/macros.h"
 #include "base/memory/ref_counted.h"
+#include "base/observer_list.h"
 #include "base/time/time.h"
 #include "cc/animation/animation.h"
 #include "cc/animation/animation_curve.h"
 #include "cc/animation/animation_export.h"
 #include "cc/animation/element_animations.h"
 #include "cc/trees/element_id.h"
 
 namespace cc {
 
 class AnimationDelegate;
 class AnimationEvents;
 class AnimationHost;
+class AnimationObserver;
 class AnimationTimeline;
 struct AnimationEvent;
 struct PropertyAnimationState;
 
 // 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.
@@ skipping 129 matching lines @@
   // thread counterpart continues producing scroll deltas until activation.
   // These scroll deltas need to be cleared at activation, so that the active
   // element's scroll offset matches the offset provided by the main thread
   // rather than a combination of this offset and scroll deltas produced by
   // the removed animation. This is to provide the illusion of synchronicity to
   // JS that simultaneously removes an animation and sets the scroll offset.
   bool scroll_offset_animation_was_interrupted() const {
     return scroll_offset_animation_was_interrupted_;
   }
 
+  // This controls the list of entities who are informed of updates as
+  // animations are ticked.
+  void AddObserver(AnimationObserver* observer);
+  void RemoveObserver(AnimationObserver* observer);
+
  private:
   friend class base::RefCounted<AnimationPlayer>;
 
   explicit AnimationPlayer(int id);
   ~AnimationPlayer();
 
   void SetNeedsCommit();
 
   void RegisterPlayer();
   void UnregisterPlayer();
@@ skipping 28 matching lines @@
 
   // Only try to start animations when new animations are added or when the
   // previous attempt at starting animations failed to start all animations.
   bool needs_to_start_animations_;
 
   // This is used to ensure that we don't spam the animation host.
   bool is_ticking_;
 
   bool scroll_offset_animation_was_interrupted_;
 
+  base::ObserverList<AnimationObserver> observers_;
+
   DISALLOW_COPY_AND_ASSIGN(AnimationPlayer);
 };
 
 }  // namespace cc
 
 #endif  // CC_ANIMATION_ANIMATION_PLAYER_H_