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

cc/layers/tiled_layer.h

 // Copyright 2011 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_LAYERS_TILED_LAYER_H_
 #define CC_LAYERS_TILED_LAYER_H_
 
 #include "cc/base/cc_export.h"
 #include "cc/layers/contents_scaling_layer.h"
 #include "cc/resources/layer_tiling_data.h"
@@ skipping 28 matching lines @@
   virtual void OnOutputSurfaceCreated() OVERRIDE;
 
  protected:
   TiledLayer();
   virtual ~TiledLayer();
 
   void UpdateTileSizeAndTilingOption();
   void UpdateBounds();
 
   // Exposed to subclasses for testing.
-  void SetTileSize(gfx::Size size);
+  void SetTileSize(const gfx::Size& size);
   void SetTextureFormat(ResourceFormat texture_format) {
     texture_format_ = texture_format;
   }
   void SetBorderTexelOption(LayerTilingData::BorderTexelOption option);
   size_t NumPaintedTiles() { return tiler_->tiles().size(); }
 
   virtual LayerUpdater* Updater() const = 0;
   virtual void CreateUpdaterIfNeeded() = 0;
 
   // Set invalidations to be potentially repainted during Update().
@@ skipping 77 matching lines @@
 
   TilingOption tiling_option_;
   scoped_ptr<LayerTilingData> tiler_;
 
   DISALLOW_COPY_AND_ASSIGN(TiledLayer);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_TILED_LAYER_H_