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

cc/resources/picture_layer_tiling_set.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_SET_H_
 #define CC_RESOURCES_PICTURE_LAYER_TILING_SET_H_
 
 #include "cc/base/region.h"
 #include "cc/base/scoped_ptr_vector.h"
 #include "cc/resources/picture_layer_tiling.h"
 #include "ui/gfx/size.h"
 
 namespace cc {
 
 class CC_EXPORT PictureLayerTilingSet {
  public:
   PictureLayerTilingSet(PictureLayerTilingClient* client,
-                        gfx::Size layer_bounds);
+                        const gfx::Size& layer_bounds);
   ~PictureLayerTilingSet();
 
   void SetClient(PictureLayerTilingClient* client);
   const PictureLayerTilingClient* client() const { return client_; }
 
   // Make this set of tilings match the same set of content scales from |other|.
   // Delete any tilings that don't meet |minimum_contents_scale|.  Recreate
   // any tiles that intersect |layer_invalidation|.  Update the size of all
   // tilings to |new_layer_bounds|.
   void SyncTilings(
      const PictureLayerTilingSet& other,
-     gfx::Size new_layer_bounds,
+     const gfx::Size& new_layer_bounds,
      const Region& layer_invalidation,
      float minimum_contents_scale);
 
   gfx::Size layer_bounds() const { return layer_bounds_; }
 
   void SetCanUseLCDText(bool can_use_lcd_text);
 
   PictureLayerTiling* AddTiling(float contents_scale);
   size_t num_tilings() const { return tilings_.size(); }
   int NumHighResTilings() const;
   PictureLayerTiling* tiling_at(size_t idx) { return tilings_[idx]; }
   const PictureLayerTiling* tiling_at(size_t idx) const {
     return tilings_[idx];
   }
 
   PictureLayerTiling* TilingAtScale(float scale) const;
 
   // Remove all tilings.
   void RemoveAllTilings();
 
   // Remove one tiling.
   void Remove(PictureLayerTiling* tiling);
 
   // Remove all tiles; keep all tilings.
   void RemoveAllTiles();
 
   void UpdateTilePriorities(
       WhichTree tree,
-      gfx::Size device_viewport,
+      const gfx::Size& device_viewport,
       const gfx::Rect& viewport_in_content_space,
       const gfx::Rect& visible_content_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);
 
   void DidBecomeActive();
   void DidBecomeRecycled();
 
@@ skipping 49 matching lines @@
   gfx::Size layer_bounds_;
   ScopedPtrVector<PictureLayerTiling> tilings_;
 
   friend class Iterator;
   DISALLOW_COPY_AND_ASSIGN(PictureLayerTilingSet);
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_PICTURE_LAYER_TILING_SET_H_