[#2] Pass gfx structs by const ref (gfx::Rect, gfx::RectF)

cc/resources/picture_pile_base.h

 // Copyright 2013 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_RESOURCES_PICTURE_PILE_BASE_H_
 #define CC_RESOURCES_PICTURE_PILE_BASE_H_
 
 #include <bitset>
 #include <list>
 #include <utility>
@@ skipping 22 matching lines @@
   gfx::Size size() const { return tiling_.total_size(); }
   void SetMinContentsScale(float min_contents_scale);
 
   void UpdateRecordedRegion();
   const Region& recorded_region() const { return recorded_region_; }
 
   int num_tiles_x() const { return tiling_.num_tiles_x(); }
   int num_tiles_y() const { return tiling_.num_tiles_y(); }
   gfx::Rect tile_bounds(int x, int y) const { return tiling_.TileBounds(x, y); }
   bool HasRecordingAt(int x, int y);
-  bool CanRaster(float contents_scale, gfx::Rect content_rect);
+  bool CanRaster(float contents_scale, const gfx::Rect& content_rect);
 
   static void ComputeTileGridInfo(gfx::Size tile_grid_size,
                                   SkTileGridPicture::TileGridInfo* info);
 
   void SetTileGridSize(gfx::Size tile_grid_size);
   TilingData& tiling() { return tiling_; }
 
   scoped_ptr<base::Value> AsValue() const;
 
  protected:
@@ skipping 32 matching lines @@
 
   void SetRecordedRegionForTesting(const Region& recorded_region) {
     recorded_region_ = recorded_region;
   }
 
   int num_raster_threads() { return num_raster_threads_; }
   int buffer_pixels() const { return tiling_.border_texels(); }
   void Clear();
 
   gfx::Rect PaddedRect(const PictureMapKey& key);
-  gfx::Rect PadRect(gfx::Rect rect);
+  gfx::Rect PadRect(const gfx::Rect& rect);
 
   // A picture pile is a tiled set of pictures. The picture map is a map of tile
   // indices to picture infos.
   PictureMap picture_map_;
   TilingData tiling_;
   Region recorded_region_;
   float min_contents_scale_;
   SkTileGridPicture::TileGridInfo tile_grid_info_;
   SkColor background_color_;
   int slow_down_raster_scale_factor_for_debug_;
   bool contents_opaque_;
   bool show_debug_picture_borders_;
   bool clear_canvas_with_debug_color_;
   int num_raster_threads_;
 
  private:
   void SetBufferPixels(int buffer_pixels);
 
   friend class base::RefCounted<PicturePileBase>;
   DISALLOW_COPY_AND_ASSIGN(PicturePileBase);
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_PICTURE_PILE_BASE_H_