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

cc/test/tiled_layer_test_common.h

Index: cc/test/tiled_layer_test_common.h
diff --git a/cc/test/tiled_layer_test_common.h b/cc/test/tiled_layer_test_common.h
index 17de6298b8e9e1694b4d745cd744fd0914f4816b..1e1aace576a201c9a19555b5c8586d233bb5250a 100644
--- a/cc/test/tiled_layer_test_common.h
+++ b/cc/test/tiled_layer_test_common.h
@@ -46,7 +46,7 @@ class FakeLayerUpdater : public LayerUpdater {
       PrioritizedResourceManager* resource) OVERRIDE;
 
   virtual void PrepareToUpdate(const gfx::Rect& content_rect,
-                               gfx::Size tile_size,
+                               const gfx::Size& tile_size,
                                float contents_width_scale,
                                float contents_height_scale,
                                gfx::Rect* resulting_opaque_rect) OVERRIDE;
@@ -139,7 +139,7 @@ class FakeTiledLayerWithScaledBounds : public FakeTiledLayer {
   explicit FakeTiledLayerWithScaledBounds(
       PrioritizedResourceManager* resource_manager);
 
-  void SetContentBounds(gfx::Size content_bounds);
+  void SetContentBounds(const gfx::Size& content_bounds);
   virtual void CalculateContentsScale(float ideal_contents_scale,
                                       float device_scale_factor,
                                       float page_scale_factor,