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

cc/resources/layer_tiling_data.cc

 // 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.
 
 #include "cc/resources/layer_tiling_data.h"
 
 #include <vector>
 
 #include "base/logging.h"
 
 namespace cc {
 
-scoped_ptr<LayerTilingData> LayerTilingData::Create(gfx::Size tile_size,
+scoped_ptr<LayerTilingData> LayerTilingData::Create(const gfx::Size& tile_size,
                                                     BorderTexelOption border) {
   return make_scoped_ptr(new LayerTilingData(tile_size, border));
 }
 
-LayerTilingData::LayerTilingData(gfx::Size tile_size, BorderTexelOption border)
+LayerTilingData::LayerTilingData(const gfx::Size& tile_size,
+                                 BorderTexelOption border)
     : tiling_data_(tile_size, gfx::Size(), border == HAS_BORDER_TEXELS) {
   SetTileSize(tile_size);
 }
 
 LayerTilingData::~LayerTilingData() {}
 
-void LayerTilingData::SetTileSize(gfx::Size size) {
+void LayerTilingData::SetTileSize(const gfx::Size& size) {
   if (tile_size() == size)
     return;
 
   reset();
 
   tiling_data_.SetMaxTextureSize(size);
 }
 
 gfx::Size LayerTilingData::tile_size() const {
   return tiling_data_.max_texture_size();
@@ skipping 68 matching lines @@
         continue;
 
       gfx::Rect tile_opaque_rect =
           gfx::IntersectRects(content_rect, tile->opaque_rect());
       opaque_region.Union(tile_opaque_rect);
     }
   }
   return opaque_region;
 }
 
-void LayerTilingData::SetBounds(gfx::Size size) {
+void LayerTilingData::SetBounds(const gfx::Size& size) {
   tiling_data_.SetTotalSize(size);
   if (size.IsEmpty()) {
     tiles_.clear();
     return;
   }
 
   // Any tiles completely outside our new bounds are invalid and should be
   // dropped.
   int left, top, right, bottom;
   ContentRectToTileIndices(
       gfx::Rect(size), &left, &top, &right, &bottom);
   std::vector<TileMapKey> invalid_tile_keys;
   for (TileMap::const_iterator it = tiles_.begin(); it != tiles_.end(); ++it) {
     if (it->first.first > right || it->first.second > bottom)
       invalid_tile_keys.push_back(it->first);
   }
   for (size_t i = 0; i < invalid_tile_keys.size(); ++i)
     tiles_.erase(invalid_tile_keys[i]);
 }
 
 }  // namespace cc