CC Animations: Port UI Browser Compositor to use compositor animation timelines.

ui/compositor/layer.h

Index: ui/compositor/layer.h
diff --git a/ui/compositor/layer.h b/ui/compositor/layer.h
index 2628fc131ca62357637fd9d8d78c5b57b5410c89..3e80538bc537a027a689c8e2e3590685e0055288 100644
--- a/ui/compositor/layer.h
+++ b/ui/compositor/layer.h
@@ -434,11 +434,8 @@ class COMPOSITOR_EXPORT Layer
   // be called once we have been added to a tree.
   void SendPendingThreadedAnimations();
 
-  void AddAnimatorsInTreeToCollection(LayerAnimatorCollection* collection);
-  void RemoveAnimatorsInTreeFromCollection(LayerAnimatorCollection* collection);
-
-  // Returns whether the layer has an animating LayerAnimator.
-  bool IsAnimating() const;
+  void SetCompositorForAnimatorsInTree(Compositor* compositor);
+  void ResetCompositorForAnimatorsInTree(Compositor* compositor);
 
   const LayerType type_;