Add a base class for objects that want to filter messages on the UI thread. ...

chrome/gpu/gpu_channel.cc

 // Copyright (c) 2010 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 "chrome/gpu/gpu_channel.h"
 
 #if defined(OS_WIN)
 #include <windows.h>
 #endif
 
@@ skipping 237 matching lines @@
 #if defined(OS_POSIX)
   // This gets called when the GpuChannel is initially created. At this
   // point, create the socketpair and assign the GPU side FD to the channel
   // name. Keep the renderer side FD as a member variable in the PluginChannel
   // to be able to transmit it through IPC.
   int gpu_fd;
   IPC::SocketPair(&gpu_fd, &renderer_fd_);
   IPC::AddChannelSocket(channel_name, gpu_fd);
 #endif
   channel_.reset(new IPC::SyncChannel(
-      channel_name, IPC::Channel::MODE_SERVER, this, NULL,
+      channel_name, IPC::Channel::MODE_SERVER, this,
       ChildProcess::current()->io_message_loop(), false,
       ChildProcess::current()->GetShutDownEvent()));
 
   return true;
 }
 
 std::string GpuChannel::GetChannelName() {
   return StringPrintf("%d.r%d", base::GetCurrentProcId(), renderer_id_);
 }