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

cc/test/pixel_test.h

 // Copyright 2013 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 "base/file_util.h"
 #include "cc/output/gl_renderer.h"
 #include "cc/output/software_renderer.h"
 #include "cc/quads/render_pass.h"
 #include "cc/test/pixel_comparator.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 41 matching lines @@
   scoped_ptr<ResourceProvider> resource_provider_;
   scoped_ptr<TextureMailboxDeleter> texture_mailbox_deleter_;
   scoped_ptr<DirectRenderer> renderer_;
   scoped_ptr<SkBitmap> result_bitmap_;
   gfx::Vector2d external_device_viewport_offset_;
   gfx::Rect external_device_clip_rect_;
 
   void SetUpGLRenderer(bool use_skia_gpu_backend);
   void SetUpSoftwareRenderer();
 
-  void ForceExpandedViewport(gfx::Size surface_expansion);
+  void ForceExpandedViewport(const gfx::Size& surface_expansion);
   void ForceViewportOffset(gfx::Vector2d viewport_offset);
   void ForceDeviceClip(const gfx::Rect& clip);
   void EnableExternalStencilTest();
 
   // RendererClient implementation.
   virtual void SetFullRootLayerDamage() OVERRIDE {}
 
  private:
   void ReadbackResult(base::Closure quit_run_loop,
                       scoped_ptr<CopyOutputResult> result);
@@ skipping 110 matching lines @@
     SoftwareRendererWithExpandedViewport>::ExpandedViewport() const {
   return true;
 }
 
 typedef RendererPixelTest<GLRenderer> GLRendererPixelTest;
 typedef RendererPixelTest<SoftwareRenderer> SoftwareRendererPixelTest;
 
 }  // namespace cc
 
 #endif  // CC_TEST_PIXEL_TEST_H_