Add gpu::MailboxHolder to hold state for a gpu::Mailbox

content/common/gpu/client/gl_helper.cc

 // Copyright (c) 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 "content/common/gpu/client/gl_helper.h"
 
 #include <queue>
 #include <string>
 
 #include "base/bind.h"
@@ skipping 688 matching lines @@
 void GLHelper::DeleteTexture(blink::WebGLId texture_id) {
   context_->deleteTexture(texture_id);
 }
 
 uint32 GLHelper::InsertSyncPoint() { return context_->insertSyncPoint(); }
 
 void GLHelper::WaitSyncPoint(uint32 sync_point) {
   context_->waitSyncPoint(sync_point);
 }
 
-gpu::Mailbox GLHelper::ProduceMailboxFromTexture(blink::WebGLId texture_id,
-                                                 uint32* sync_point) {
+gpu::MailboxHolder GLHelper::ProduceMailboxHolderFromTexture(
+    blink::WebGLId texture_id) {
   gpu::Mailbox mailbox;
   context_->genMailboxCHROMIUM(mailbox.name);
-  if (mailbox.IsZero()) {
-    *sync_point = 0;
-    return mailbox;
-  }
+  if (mailbox.IsZero())
+    return gpu::MailboxHolder();
   content::ScopedTextureBinder<GL_TEXTURE_2D> texture_binder(context_,
                                                              texture_id);
   context_->produceTextureCHROMIUM(GL_TEXTURE_2D, mailbox.name);
-  *sync_point = context_->insertSyncPoint();
-  return mailbox;
+  return gpu::MailboxHolder(
+      mailbox, GL_TEXTURE_2D, context_->insertSyncPoint());
 }
 
 blink::WebGLId GLHelper::ConsumeMailboxToTexture(const gpu::Mailbox& mailbox,
                                                   uint32 sync_point) {
   if (mailbox.IsZero())
     return 0;
   if (sync_point)
     context_->waitSyncPoint(sync_point);
   blink::WebGLId texture = CreateTexture();
   content::ScopedTextureBinder<GL_TEXTURE_2D> texture_binder(context_,
@@ skipping 352 matching lines @@
       quality,
       src_size,
       src_subrect,
       dst_size,
       dst_subrect,
       flip_vertically,
       use_mrt);
 }
 
 }  // namespace content