cc: Add support for partial swaps when using impl-side painting.

cc/resources/tile_manager.h

Index: cc/resources/tile_manager.h
diff --git a/cc/resources/tile_manager.h b/cc/resources/tile_manager.h
index a4eddb9becc5e51f0aa22687499111f45c5560e3..5983212bcbcb90be740302d1e05cf68fe30db55a 100644
--- a/cc/resources/tile_manager.h
+++ b/cc/resources/tile_manager.h
@@ -131,6 +131,10 @@ class CC_EXPORT TileManager : public RasterWorkerPoolClient,
     }
   }
 
+  void ResetDamagedRect();
+
+  gfx::Rect GetDamagedRect();
+
  protected:
   TileManager(TileManagerClient* client,
               base::SequencedTaskRunner* task_runner,
@@ -250,6 +254,7 @@ class CC_EXPORT TileManager : public RasterWorkerPoolClient,
   std::vector<scoped_refptr<internal::Task> > orphan_raster_tasks_;
 
   std::vector<PictureLayerImpl*> layers_;
+  gfx::Rect damage_rect_;
 
   DISALLOW_COPY_AND_ASSIGN(TileManager);
 };