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

cc/layers/tiled_layer.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/layers/tiled_layer.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "base/auto_reset.h"
@@ skipping 140 matching lines @@
   // Invalidate any areas that the new bounds exposes.
   Region old_region = gfx::Rect(old_bounds);
   Region new_region = gfx::Rect(new_bounds);
   new_region.Subtract(old_region);
   for (Region::Iterator new_rects(new_region);
        new_rects.has_rect();
        new_rects.next())
     InvalidateContentRect(new_rects.rect());
 }
 
-void TiledLayer::SetTileSize(gfx::Size size) { tiler_->SetTileSize(size); }
+void TiledLayer::SetTileSize(const gfx::Size& size) {
+  tiler_->SetTileSize(size);
+}
 
 void TiledLayer::SetBorderTexelOption(
     LayerTilingData::BorderTexelOption border_texel_option) {
   tiler_->SetBorderTexelOption(border_texel_option);
 }
 
 bool TiledLayer::DrawsContent() const {
   if (!ContentsScalingLayer::DrawsContent())
     return false;
 
@@ skipping 739 matching lines @@
   gfx::Rect prepaint_rect = visible_content_rect();
   prepaint_rect.Inset(-tiler_->tile_size().width() * kPrepaintColumns,
                       -tiler_->tile_size().height() * kPrepaintRows);
   gfx::Rect content_rect(content_bounds());
   prepaint_rect.Intersect(content_rect);
 
   return prepaint_rect;
 }
 
 }  // namespace cc