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

cc/quads/checkerboard_draw_quad.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/quads/checkerboard_draw_quad.h"
 
 #include "base/logging.h"
 #include "base/values.h"
 
 namespace cc {
 
 CheckerboardDrawQuad::CheckerboardDrawQuad() : color(0) {}
 
 scoped_ptr<CheckerboardDrawQuad> CheckerboardDrawQuad::Create() {
   return make_scoped_ptr(new CheckerboardDrawQuad);
 }
 
 void CheckerboardDrawQuad::SetNew(const SharedQuadState* shared_quad_state,
-                                  gfx::Rect rect,
+                                  const gfx::Rect& rect,
                                   SkColor color) {
   gfx::Rect opaque_rect = SkColorGetA(color) == 255 ? rect : gfx::Rect();
   gfx::Rect visible_rect = rect;
   bool needs_blending = false;
   DrawQuad::SetAll(shared_quad_state, DrawQuad::CHECKERBOARD, rect, opaque_rect,
                    visible_rect, needs_blending);
   this->color = color;
 }
 
 void CheckerboardDrawQuad::SetAll(const SharedQuadState* shared_quad_state,
-                                  gfx::Rect rect,
-                                  gfx::Rect opaque_rect,
-                                  gfx::Rect visible_rect,
+                                  const gfx::Rect& rect,
+                                  const gfx::Rect& opaque_rect,
+                                  const gfx::Rect& visible_rect,
                                   bool needs_blending,
                                   SkColor color) {
   DrawQuad::SetAll(shared_quad_state, DrawQuad::CHECKERBOARD, rect, opaque_rect,
                    visible_rect, needs_blending);
   this->color = color;
 }
 
 void CheckerboardDrawQuad::IterateResources(
     const ResourceIteratorCallback& callback) {}
 
 const CheckerboardDrawQuad* CheckerboardDrawQuad::MaterialCast(
     const DrawQuad* quad) {
   DCHECK(quad->material == DrawQuad::CHECKERBOARD);
   return static_cast<const CheckerboardDrawQuad*>(quad);
 }
 
 void CheckerboardDrawQuad::ExtendValue(base::DictionaryValue* value) const {
   value->SetInteger("color", color);
 }
 
 }  // namespace cc