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

cc/base/math_util.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/base/math_util.h"
 
 #include <algorithm>
 #include <cmath>
 #include <limits>
 
@@ skipping 84 matching lines @@
 }
 
 static inline void AddVertexToClippedQuad(gfx::PointF new_vertex,
                                           gfx::PointF clipped_quad[8],
                                           int* num_vertices_in_clipped_quad) {
   clipped_quad[*num_vertices_in_clipped_quad] = new_vertex;
   (*num_vertices_in_clipped_quad)++;
 }
 
 gfx::Rect MathUtil::MapClippedRect(const gfx::Transform& transform,
-                                   gfx::Rect src_rect) {
+                                   const gfx::Rect& src_rect) {
   return gfx::ToEnclosingRect(MapClippedRect(transform, gfx::RectF(src_rect)));
 }
 
 gfx::RectF MathUtil::MapClippedRect(const gfx::Transform& transform,
                                     const gfx::RectF& src_rect) {
   if (transform.IsIdentityOrTranslation()) {
     return src_rect +
            gfx::Vector2dF(SkMScalarToFloat(transform.matrix().get(0, 3)),
                           SkMScalarToFloat(transform.matrix().get(1, 3)));
   }
@@ skipping 398 matching lines @@
   return res.PassAs<base::Value>();
 }
 
 scoped_ptr<base::Value> MathUtil::AsValue(gfx::SizeF s) {
   scoped_ptr<base::DictionaryValue> res(new base::DictionaryValue());
   res->SetDouble("width", s.width());
   res->SetDouble("height", s.height());
   return res.PassAs<base::Value>();
 }
 
-scoped_ptr<base::Value> MathUtil::AsValue(gfx::Rect r) {
+scoped_ptr<base::Value> MathUtil::AsValue(const gfx::Rect& r) {
   scoped_ptr<base::ListValue> res(new base::ListValue());
   res->AppendInteger(r.x());
   res->AppendInteger(r.y());
   res->AppendInteger(r.width());
   res->AppendInteger(r.height());
   return res.PassAs<base::Value>();
 }
 
 bool MathUtil::FromValue(const base::Value* raw_value, gfx::Rect* out_rect) {
   const base::ListValue* value = NULL;
@@ skipping 70 matching lines @@
   return scoped_ptr<base::Value>(base::Value::CreateDoubleValue(
       std::min(value, std::numeric_limits<double>::max())));
 }
 
 scoped_ptr<base::Value> MathUtil::AsValueSafely(float value) {
   return scoped_ptr<base::Value>(base::Value::CreateDoubleValue(
       std::min(value, std::numeric_limits<float>::max())));
 }
 
 }  // namespace cc