Add a flag to disable partial raster in renderer

cc/tiles/picture_layer_tiling.h

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_TILES_PICTURE_LAYER_TILING_H_
 #define CC_TILES_PICTURE_LAYER_TILING_H_
 
 #include <map>
 #include <utility>
 #include <vector>
@@ skipping 28 matching lines @@
   virtual ScopedTilePtr CreateTile(const Tile::CreateInfo& info) = 0;
   virtual gfx::Size CalculateTileSize(
     const gfx::Size& content_bounds) const = 0;
   // This invalidation region defines the area (if any, it can by null) that
   // tiles can not be shared between pending and active trees.
   virtual const Region* GetPendingInvalidation() = 0;
   virtual const PictureLayerTiling* GetPendingOrActiveTwinTiling(
       const PictureLayerTiling* tiling) const = 0;
   virtual bool HasValidTilePriorities() const = 0;
   virtual bool RequiresHighResToDraw() const = 0;
+  virtual bool IsPartialRasterEnabled() const = 0;
 
  protected:
   virtual ~PictureLayerTilingClient() {}
 };
 
 struct TileMapKey {
   TileMapKey(int x, int y) : index_x(x), index_y(y) {}
   explicit TileMapKey(const std::pair<int, int>& index)
       : index_x(index.first), index_y(index.second) {}
 
@@ skipping 347 matching lines @@
   bool has_eventually_rect_tiles_;
   bool all_tiles_done_;
 
  private:
   DISALLOW_ASSIGN(PictureLayerTiling);
 };
 
 }  // namespace cc
 
 #endif  // CC_TILES_PICTURE_LAYER_TILING_H_