cc: Don't pass simple well-defined classes by reference.

cc/resources/resource.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/resources/resource.h"
 #include "third_party/khronos/GLES2/gl2ext.h"
 
 namespace cc {
 
-void Resource::set_dimensions(const gfx::Size& size, GLenum format) {
-  size_ = size;
-  format_ = format;
-}
-
 size_t Resource::bytes() const {
   if (size_.IsEmpty())
     return 0;
 
   return MemorySizeBytes(size_, format_);
 }
 
 size_t Resource::BytesPerPixel(GLenum format) {
   size_t components_per_pixel = 0;
   size_t bytes_per_component = 1;
   switch (format) {
     case GL_RGBA:
     case GL_BGRA_EXT:
       components_per_pixel = 4;
       break;
     case GL_LUMINANCE:
       components_per_pixel = 1;
       break;
     default:
       NOTREACHED();
   }
   return components_per_pixel * bytes_per_component;
 }
 
-size_t Resource::MemorySizeBytes(const gfx::Size& size, GLenum format) {
+size_t Resource::MemorySizeBytes(gfx::Size size, GLenum format) {
   return BytesPerPixel(format) * size.width() * size.height();
 }
 
 
 }  // namespace cc