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

cc/test/skia_common.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/test/skia_common.h"
 
 #include "cc/resources/picture.h"
 #include "skia/ext/refptr.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "ui/gfx/rect.h"
 #include "ui/gfx/skia_util.h"
 
 namespace cc {
 
 void DrawPicture(unsigned char* buffer,
                  const gfx::Rect& layer_rect,
                  scoped_refptr<Picture> picture) {
   SkBitmap bitmap;
   bitmap.setConfig(SkBitmap::kARGB_8888_Config,
                    layer_rect.width(),
                    layer_rect.height());
   bitmap.setPixels(buffer);
   SkCanvas canvas(bitmap);
   canvas.clipRect(gfx::RectToSkRect(layer_rect));
   picture->Raster(&canvas, NULL, layer_rect, 1.0f);
 }
 
-void CreateBitmap(gfx::Size size, const char* uri, SkBitmap* bitmap) {
+void CreateBitmap(const gfx::Size& size, const char* uri, SkBitmap* bitmap) {
   SkImageInfo info = {
     size.width(),
     size.height(),
     kPMColor_SkColorType,
     kPremul_SkAlphaType
   };
 
   bitmap->setConfig(info);
   bitmap->allocPixels();
   bitmap->pixelRef()->setImmutable();
   bitmap->pixelRef()->setURI(uri);
 }
 
 }  // namespace cc