[#2] Pass gfx structs by const ref (gfx::Rect, gfx::RectF)

cc/layers/tiled_layer_impl_unittest.cc

 // 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.
 
 #include "cc/layers/tiled_layer_impl.h"
 
 #include "cc/layers/append_quads_data.h"
 #include "cc/quads/tile_draw_quad.h"
 #include "cc/resources/layer_tiling_data.h"
 #include "cc/test/fake_impl_proxy.h"
@@ skipping 54 matching lines @@
     }
 
     return layer.Pass();
   }
 
   void GetQuads(QuadList* quads,
                 SharedQuadStateList* shared_states,
                 gfx::Size tile_size,
                 gfx::Size layer_size,
                 LayerTilingData::BorderTexelOption border_texel_option,
-                gfx::Rect visible_content_rect) {
+                const gfx::Rect& visible_content_rect) {
     scoped_ptr<TiledLayerImpl> layer =
         CreateLayer(tile_size, layer_size, border_texel_option);
     layer->draw_properties().visible_content_rect = visible_content_rect;
     layer->SetBounds(layer_size);
 
     MockQuadCuller quad_culler(quads, shared_states);
     AppendQuadsData data;
     layer->AppendQuads(&quad_culler, &data);
   }
 
@@ skipping 213 matching lines @@
   ResourceProvider::ResourceId empty_resource(0);
   layer->PushTileProperties(0, 1, empty_resource, gfx::Rect(0, 0, 1, 1), false);
   layer->PushTileProperties(2, 3, empty_resource, gfx::Rect(0, 0, 1, 1), false);
   layer->PushTileProperties(2, 0, empty_resource, gfx::Rect(0, 0, 1, 1), false);
 
   EXPECT_EQ(layer->GPUMemoryUsageInBytes(), 0u);
 }
 
 }  // namespace
 }  // namespace cc