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

content/renderer/pepper/pepper_graphics_2d_host.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/renderer/pepper/pepper_graphics_2d_host.h"
 
 #include "base/bind.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 602 matching lines @@
 
 int32_t PepperGraphics2DHost::OnHostMsgReadImageData(
     ppapi::host::HostMessageContext* context,
     PP_Resource image,
     const PP_Point& top_left) {
   context->reply_msg = PpapiPluginMsg_Graphics2D_ReadImageDataAck();
   return ReadImageData(image, &top_left) ? PP_OK : PP_ERROR_FAILED;
 }
 
 void ReleaseCallback(scoped_ptr<base::SharedMemory> memory,
-                     unsigned sync_point,
+                     uint32 sync_point,
                      bool lost_resource) {}
 
 bool PepperGraphics2DHost::PrepareTextureMailbox(
     cc::TextureMailbox* mailbox,
     scoped_ptr<cc::SingleReleaseCallback>* release_callback) {
   if (!texture_mailbox_modified_)
     return false;
   // TODO(jbauman): Send image_data_ through mailbox to avoid copy.
   gfx::Size pixel_image_size(image_data_->width(), image_data_->height());
   int buffer_size = pixel_image_size.GetArea() * 4;
@@ skipping 247 matching lines @@
     gfx::Point inverse_scaled_point =
         gfx::ToFlooredPoint(gfx::ScalePoint(*delta, inverse_scale));
     if (original_delta != inverse_scaled_point)
       return false;
   }
 
   return true;
 }
 
 }  // namespace content