cc: Split animating and drawing into separate actions

cc/scheduler/scheduler.h

Index: cc/scheduler/scheduler.h
diff --git a/cc/scheduler/scheduler.h b/cc/scheduler/scheduler.h
index 7d577b0187ac334a9324f407990121a2f082eeb2..61b8373fef770778f9ece9825a2c5ecbce84e693 100644
--- a/cc/scheduler/scheduler.h
+++ b/cc/scheduler/scheduler.h
@@ -29,6 +29,7 @@ class SchedulerClient {
   virtual DrawSwapReadbackResult ScheduledActionDrawAndSwapIfPossible() = 0;
   virtual DrawSwapReadbackResult ScheduledActionDrawAndSwapForced() = 0;
   virtual DrawSwapReadbackResult ScheduledActionDrawAndReadback() = 0;
+  virtual void ScheduledActionAnimate() = 0;
   virtual void ScheduledActionCommit() = 0;
   virtual void ScheduledActionUpdateVisibleTiles() = 0;
   virtual void ScheduledActionActivatePendingTree() = 0;
@@ -72,6 +73,8 @@ class CC_EXPORT Scheduler {
 
   void SetNeedsRedraw();
 
+  void SetNeedsAnimate();
+
   void SetNeedsManageTiles();
 
   void SetMainThreadNeedsLayerTextures();