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

ppapi/proxy/dispatcher.cc

Index: ppapi/proxy/dispatcher.cc
===================================================================
--- ppapi/proxy/dispatcher.cc	(revision 67520)
+++ ppapi/proxy/dispatcher.cc	(working copy)
@@ -73,7 +73,7 @@
                                  base::WaitableEvent* shutdown_event) {
   IPC::Channel::Mode mode = is_client ? IPC::Channel::MODE_CLIENT
                                       : IPC::Channel::MODE_SERVER;
-  channel_.reset(new IPC::SyncChannel(channel_name, mode, this, NULL,
+  channel_.reset(new IPC::SyncChannel(channel_name, mode, this,
                                       ipc_message_loop, false, shutdown_event));
   return true;
 }