[#7] Resubmitted - Pass gfx structs by const ref (gfx::Size)

cc/resources/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_RESOURCES_PICTURE_LAYER_TILING_H_
 #define CC_RESOURCES_PICTURE_LAYER_TILING_H_
 
 #include <utility>
 #include <vector>
 
@@ skipping 13 matching lines @@
 
 class CC_EXPORT PictureLayerTilingClient {
  public:
   // Create a tile at the given content_rect (in the contents scale of the
   // tiling) This might return null if the client cannot create such a tile.
   virtual scoped_refptr<Tile> CreateTile(
     PictureLayerTiling* tiling,
     const gfx::Rect& content_rect) = 0;
   virtual void UpdatePile(Tile* tile) = 0;
   virtual gfx::Size CalculateTileSize(
-    gfx::Size content_bounds) const = 0;
+    const gfx::Size& content_bounds) const = 0;
   virtual const Region* GetInvalidation() = 0;
   virtual const PictureLayerTiling* GetTwinTiling(
       const PictureLayerTiling* tiling) const = 0;
 
  protected:
   virtual ~PictureLayerTilingClient() {}
 };
 
 class CC_EXPORT PictureLayerTiling {
  public:
   ~PictureLayerTiling();
 
   // Create a tiling with no tiles.  CreateTiles must be called to add some.
   static scoped_ptr<PictureLayerTiling> Create(
       float contents_scale,
-      gfx::Size layer_bounds,
+      const gfx::Size& layer_bounds,
       PictureLayerTilingClient* client);
   gfx::Size layer_bounds() const { return layer_bounds_; }
-  void SetLayerBounds(gfx::Size layer_bounds);
+  void SetLayerBounds(const gfx::Size& layer_bounds);
   void Invalidate(const Region& layer_region);
   void CreateMissingTilesInLiveTilesRect();
 
   void SetCanUseLCDText(bool can_use_lcd_text);
 
   void SetClient(PictureLayerTilingClient* client);
   void set_resolution(TileResolution resolution) { resolution_ = resolution; }
   TileResolution resolution() const { return resolution_; }
 
   gfx::Rect ContentRect() const;
@@ skipping 64 matching lines @@
 
     friend class PictureLayerTiling;
   };
 
   Region OpaqueRegionInContentRect(const gfx::Rect& content_rect) const;
 
   void Reset();
 
   void UpdateTilePriorities(
       WhichTree tree,
-      gfx::Size device_viewport,
+      const gfx::Size& device_viewport,
       const gfx::Rect& viewport_in_layer_space,
       const gfx::Rect& visible_layer_rect,
-      gfx::Size last_layer_bounds,
-      gfx::Size current_layer_bounds,
+      const gfx::Size& last_layer_bounds,
+      const gfx::Size& current_layer_bounds,
       float last_layer_contents_scale,
       float current_layer_contents_scale,
       const gfx::Transform& last_screen_transform,
       const gfx::Transform& current_screen_transform,
       double current_frame_time_in_seconds,
       size_t max_tiles_for_interest_area);
 
   // Copies the src_tree priority into the dst_tree priority for all tiles.
   // The src_tree priority is reset to the lowest priority possible.  This
   // also updates the pile on each tile to be the current client's pile.
@@ skipping 33 matching lines @@
 
   bool has_ever_been_updated() const {
     return last_impl_frame_time_in_seconds_ != 0.0;
   }
 
  protected:
   typedef std::pair<int, int> TileMapKey;
   typedef base::hash_map<TileMapKey, scoped_refptr<Tile> > TileMap;
 
   PictureLayerTiling(float contents_scale,
-                     gfx::Size layer_bounds,
+                     const gfx::Size& layer_bounds,
                      PictureLayerTilingClient* client);
   void SetLiveTilesRect(const gfx::Rect& live_tiles_rect);
   void CreateTile(int i, int j, const PictureLayerTiling* twin_tiling);
 
   // Given properties.
   float contents_scale_;
   gfx::Size layer_bounds_;
   TileResolution resolution_;
   PictureLayerTilingClient* client_;
 
   // Internal data.
   TilingData tiling_data_;
   TileMap tiles_;  // It is not legal to have a NULL tile in the tiles_ map.
   gfx::Rect live_tiles_rect_;
 
   // State saved for computing velocities based upon finite differences.
   double last_impl_frame_time_in_seconds_;
 
   friend class CoverageIterator;
 
  private:
   DISALLOW_ASSIGN(PictureLayerTiling);
 
   RectExpansionCache expansion_cache_;
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_PICTURE_LAYER_TILING_H_