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

cc/resources/scoped_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/scoped_resource.h"
 
 namespace cc {
 
 ScopedResource::ScopedResource(ResourceProvider* resource_provider)
     : resource_provider_(resource_provider) {
   DCHECK(resource_provider_);
 }
 
 ScopedResource::~ScopedResource() {
   Free();
 }
 
-bool ScopedResource::Allocate(const gfx::Size& size, GLenum format,
+bool ScopedResource::Allocate(gfx::Size size,
+                              GLenum format,
                               ResourceProvider::TextureUsageHint hint) {
   DCHECK(!id());
   DCHECK(!size.IsEmpty());
 
   set_dimensions(size, format);
   set_id(resource_provider_->CreateResource(size, format, hint));
 
 #ifndef NDEBUG
   allocate_thread_id_ = base::PlatformThread::CurrentId();
 #endif
 
   return id() != 0;
 }
 
 void ScopedResource::Free() {
   if (id()) {
 #ifndef NDEBUG
     DCHECK(allocate_thread_id_ == base::PlatformThread::CurrentId());
 #endif
     resource_provider_->DeleteResource(id());
   }
   set_id(0);
 }
 
 void ScopedResource::Leak() {
   set_id(0);
 }
 
 }  // namespace cc