Revert of [#7] Pass gfx structs by const ref (gfx::Size)

cc/output/copy_output_result.cc

 // Copyright 2013 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/output/copy_output_result.h"
 
 #include "base/logging.h"
 #include "cc/resources/single_release_callback.h"
 #include "cc/resources/texture_mailbox.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 
 namespace cc {
 
 CopyOutputResult::CopyOutputResult() {}
 
 CopyOutputResult::CopyOutputResult(scoped_ptr<SkBitmap> bitmap)
     : size_(bitmap->width(), bitmap->height()),
       bitmap_(bitmap.Pass()) {
   DCHECK(bitmap_);
 }
 
 CopyOutputResult::CopyOutputResult(
-    const gfx::Size& size,
+    gfx::Size size,
     const TextureMailbox& texture_mailbox,
     scoped_ptr<SingleReleaseCallback> release_callback)
     : size_(size),
       texture_mailbox_(texture_mailbox),
       release_callback_(release_callback.Pass()) {
   DCHECK(texture_mailbox_.IsTexture());
 }
 
 CopyOutputResult::~CopyOutputResult() {
   if (release_callback_)
     release_callback_->Run(0, false);
 }
 
 scoped_ptr<SkBitmap> CopyOutputResult::TakeBitmap() {
   return bitmap_.Pass();
 }
 
 void CopyOutputResult::TakeTexture(
     TextureMailbox* texture_mailbox,
     scoped_ptr<SingleReleaseCallback>* release_callback) {
   *texture_mailbox = texture_mailbox_;
   *release_callback = release_callback_.Pass();
 
   texture_mailbox_ = TextureMailbox();
 }
 
 }  // namespace cc