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

cc/test/fake_content_layer_client.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/fake_content_layer_client.h"
 
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "ui/gfx/skia_util.h"
 
 namespace cc {
 
 FakeContentLayerClient::FakeContentLayerClient()
     : paint_all_opaque_(false) {
 }
 
 FakeContentLayerClient::~FakeContentLayerClient() {
 }
 
 void FakeContentLayerClient::PaintContents(SkCanvas* canvas,
-    gfx::Rect paint_rect, gfx::RectF* opaque_rect) {
+    const gfx::Rect& paint_rect, gfx::RectF* opaque_rect) {
   if (paint_all_opaque_)
     *opaque_rect = paint_rect;
 
   canvas->clipRect(gfx::RectToSkRect(paint_rect));
   for (RectPaintVector::const_iterator it = draw_rects_.begin();
       it != draw_rects_.end(); ++it) {
     const gfx::RectF& draw_rect = it->first;
     const SkPaint& paint = it->second;
     canvas->drawRectCoords(draw_rect.x(),
                            draw_rect.y(),
                            draw_rect.right(),
                            draw_rect.bottom(),
                            paint);
   }
 
   for (BitmapVector::const_iterator it = draw_bitmaps_.begin();
       it != draw_bitmaps_.end(); ++it) {
     canvas->drawBitmap(it->bitmap, it->point.x(), it->point.y(), &it->paint);
   }
 }
 
 }  // namespace cc