Ref count layer animation controllers.

cc/layer_tree_impl.h

Index: cc/layer_tree_impl.h
diff --git a/cc/layer_tree_impl.h b/cc/layer_tree_impl.h
index 8b7c925339ebf1a9e51f2f1eed7cdbfb04202299..bd7fdda81c98a7f69fe350fa45f71fced351984a 100644
--- a/cc/layer_tree_impl.h
+++ b/cc/layer_tree_impl.h
@@ -6,6 +6,7 @@
 #define CC_LAYER_TREE_IMPL_H_
 
 #include "base/hash_tables.h"
+#include "cc/animation_registrar.h"
 #include "cc/layer_impl.h"
 
 #if defined(COMPILER_GCC)
@@ -32,7 +33,7 @@ class OutputSurface;
 class ResourceProvider;
 class TileManager;
 
-class CC_EXPORT LayerTreeImpl {
+class CC_EXPORT LayerTreeImpl : public AnimationRegistrar {
  public:
   static scoped_ptr<LayerTreeImpl> create(LayerTreeHostImpl* layer_tree_host_impl)
   {
@@ -95,6 +96,13 @@ class CC_EXPORT LayerTreeImpl {
 protected:
   LayerTreeImpl(LayerTreeHostImpl* layer_tree_host_impl);
 
+  // AnimationRegistrar implementation.
+  virtual scoped_refptr<LayerAnimationController> GetAnimationControllerForId(int id) OVERRIDE;
+  virtual void DidActivateAnimationController(LayerAnimationController*) OVERRIDE;
+  virtual void DidDeactivateAnimationController(LayerAnimationController*) OVERRIDE;
+  virtual void RegisterAnimationController(LayerAnimationController*) OVERRIDE;
+  virtual void UnregisterAnimationController(LayerAnimationController*) OVERRIDE;
+
   LayerTreeHostImpl* layer_tree_host_impl_;
   int source_frame_number_;
   scoped_ptr<LayerImpl> root_layer_;