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

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/SkBitmapDevice.h"
 #include "ui/gfx/rect.h"
@@ skipping 14 matching lines @@
 
 SkPixelRef* TestPixelRef::deepCopy(
     SkBitmap::Config config,
     const SkIRect* subset) {
   this->ref();
   return this;
 }
 
 
 void DrawPicture(unsigned char* buffer,
-                 gfx::Rect layer_rect,
+                 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);
   SkBitmapDevice device(bitmap);
   SkCanvas canvas(&device);
   canvas.clipRect(gfx::RectToSkRect(layer_rect));
   picture->Raster(&canvas, NULL, layer_rect, 1.0f);
@@ skipping 10 matching lines @@
   skia::RefPtr<TestPixelRef> pixel_ref =
       skia::AdoptRef(new TestPixelRef(info));
   pixel_ref->setURI(uri);
 
   bitmap->setConfig(info);
   bitmap->setPixelRef(pixel_ref.get());
 }
 
 
 }  // namespace cc