[DRAFT] Animations: Profile hash look-ups for external mutators

cc/trees/layer_tree_host.h

Index: cc/trees/layer_tree_host.h
diff --git a/cc/trees/layer_tree_host.h b/cc/trees/layer_tree_host.h
index b491f1577b355f4d9337bf4498fef95d654e2dd5..62456e0ea9bc24edea1a2dbfddc85b5a9f067b4d 100644
--- a/cc/trees/layer_tree_host.h
+++ b/cc/trees/layer_tree_host.h
@@ -120,7 +120,7 @@ class CC_EXPORT LayerTreeHost : public LayerTreeMutatorsClient {
       LayerTreeHostImplClient* client);
   void DidLoseOutputSurface();
   bool output_surface_lost() const { return output_surface_lost_; }
-  void DidCommitAndDrawFrame() { client_->DidCommitAndDrawFrame(); }
+  void DidCommitAndDrawFrame();
   void DidCompleteSwapBuffers() { client_->DidCompleteSwapBuffers(); }
   void DeleteContentsTexturesOnImplThread(ResourceProvider* resource_provider);
   bool UpdateLayers(ResourceUpdateQueue* queue);
@@ -363,6 +363,8 @@ class CC_EXPORT LayerTreeHost : public LayerTreeMutatorsClient {
   bool HasAnyAnimation(const Layer* layer) const;
   bool HasActiveAnimation(const Layer* layer) const;
 
+  void ReportAndClearStatsAfterAnimateLayers();
+
  protected:
   explicit LayerTreeHost(InitParams* params);
   void InitializeThreaded(
@@ -519,6 +521,7 @@ class CC_EXPORT LayerTreeHost : public LayerTreeMutatorsClient {
 
   typedef base::hash_map<int, Layer*> LayerIdMap;
   LayerIdMap layer_id_map_;
+  mutable base::TimeDelta find_layer_by_id_stats_;
 
   uint32_t surface_id_namespace_;
   uint32_t next_surface_sequence_;