cc: Split animating and drawing into separate actions

cc/trees/layer_tree_host_impl.h

Index: cc/trees/layer_tree_host_impl.h
diff --git a/cc/trees/layer_tree_host_impl.h b/cc/trees/layer_tree_host_impl.h
index 10477dc2af297d281ab1eefeac22c6a87fe16893..d7f0ae85d49e4f0a471d1009789e8c91e40f65da 100644
--- a/cc/trees/layer_tree_host_impl.h
+++ b/cc/trees/layer_tree_host_impl.h
@@ -66,10 +66,12 @@ class LayerTreeHostImplClient {
   virtual void BeginImplFrame(const BeginFrameArgs& args) = 0;
   virtual void OnCanDrawStateChanged(bool can_draw) = 0;
   virtual void NotifyReadyToActivate() = 0;
-  // Please call these 2 functions through
-  // LayerTreeHostImpl's SetNeedsRedraw() and SetNeedsRedrawRect().
+  // Please call these 3 functions through
+  // LayerTreeHostImpl's SetNeedsRedraw(), SetNeedsRedrawRect() and
+  // SetNeedsAnimate().
   virtual void SetNeedsRedrawOnImplThread() = 0;
   virtual void SetNeedsRedrawRectOnImplThread(const gfx::Rect& damage_rect) = 0;
+  virtual void SetNeedsAnimateOnImplThread() = 0;
   virtual void DidInitializeVisibleTileOnImplThread() = 0;
   virtual void SetNeedsCommitOnImplThread() = 0;
   virtual void SetNeedsManageTilesOnImplThread() = 0;
@@ -295,6 +297,7 @@ class CC_EXPORT LayerTreeHostImpl
 
   void SetNeedsCommit() { client_->SetNeedsCommitOnImplThread(); }
   void SetNeedsRedraw();
+  void SetNeedsAnimate();
 
   ManagedMemoryPolicy ActualManagedMemoryPolicy() const;