Use gpu::Mailbox in IPCs instead of std::string

content/browser/browser_plugin/browser_plugin_guest_manager.cc

 // Copyright (c) 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 "content/browser/browser_plugin/browser_plugin_guest_manager.h"
 
 #include "base/command_line.h"
 #include "content/browser/browser_plugin/browser_plugin_guest.h"
 #include "content/browser/browser_plugin/browser_plugin_host_factory.h"
 #include "content/browser/renderer_host/render_view_host_impl.h"
@@ skipping 193 matching lines @@
   }
   return NULL;
 }
 
 // We only get here during teardown if we have one last buffer pending,
 // otherwise the ACK is handled by the guest.
 void BrowserPluginGuestManager::OnUnhandledSwapBuffersACK(
     int instance_id,
     int route_id,
     int gpu_host_id,
-    const std::string& mailbox_name,
+    const gpu::Mailbox& mailbox_name,
     uint32 sync_point) {
   BrowserPluginGuest::AcknowledgeBufferPresent(route_id,
                                                gpu_host_id,
                                                mailbox_name,
                                                sync_point);
 }
 
 }  // namespace content