cc: Rasterize cheap tiles immediately

cc/tile_manager.h

Index: cc/tile_manager.h
diff --git a/cc/tile_manager.h b/cc/tile_manager.h
index 631469d5c6d9a4e1b4305a03f052a3961c4005f9..054ebe830604b06af381d2d2aa75d3919740c473 100644
--- a/cc/tile_manager.h
+++ b/cc/tile_manager.h
@@ -27,6 +27,8 @@ class CC_EXPORT TileManagerClient {
  public:
   virtual void ScheduleManageTiles() = 0;
   virtual void DidUploadVisibleHighResolutionTile() = 0;
+  virtual bool CanDoAnotherCheapRaster() const = 0;
+  virtual void DidPerformCheapRaster() = 0;
 
  protected:
   virtual ~TileManagerClient() {}
@@ -145,10 +147,11 @@ class CC_EXPORT TileManager {
       scoped_refptr<Tile> tile, skia::LazyPixelRef* pixel_ref);
   void OnImageDecodeTaskCompleted(
       scoped_refptr<Tile> tile, uint32_t pixel_ref_id);
-  bool CanDispatchRasterTask(Tile* tile);
+  bool CanDispatchRasterTask(Tile* tile) const;
+  bool CanPerformCheapRaster(Tile* tile) const;
   scoped_ptr<ResourcePool::Resource> PrepareTileForRaster(Tile* tile);
   void DispatchOneRasterTask(scoped_refptr<Tile> tile);
-  void PerformOneRaster(Tile* tile);
+  void PerformOneCheapRaster(Tile* tile);
   void OnRasterCompleted(
       scoped_refptr<Tile> tile,
       scoped_ptr<ResourcePool::Resource> resource,
@@ -170,7 +173,7 @@ class CC_EXPORT TileManager {
                             bool use_cheapness_estimator,
                             PicturePileImpl* picture_pile,
                             RenderingStats* stats);
-  static void RunImageDecodeTask(skia::LazyPixelRef* pixel_ref,
+  static void PerformImageDecode(skia::LazyPixelRef* pixel_ref,
                                  RenderingStats* stats);
 
   static void RecordCheapnessPredictorResults(bool is_predicted_cheap,