Add a mechanism to extend a libevent based message pump.

message_loop/message_loop.h

 // Copyright 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.
 
 #ifndef BASE_MESSAGE_LOOP_MESSAGE_LOOP_H_
 #define BASE_MESSAGE_LOOP_MESSAGE_LOOP_H_
 
 #include <queue>
 #include <string>
 
@@ skipping 584 matching lines @@
 
 #if defined(USE_OZONE) || (defined(USE_X11) && !defined(USE_GLIB))
   // Please see MessagePumpLibevent for definition.
   bool WatchFileDescriptor(
       int fd,
       bool persistent,
       MessagePumpLibevent::Mode mode,
       MessagePumpLibevent::FileDescriptorWatcher* controller,
       MessagePumpLibevent::Watcher* delegate);
 #endif
+
+#if defined(USE_X11)
+  // Please see MessagePumpLibevent for definition.
+  void SetEventSource(MessagePumpLibevent::EventSource* event_source);
+  void ClearEventSource();
+#endif
 };
 
 // Do not add any member variables to MessageLoopForUI!  This is important b/c
 // MessageLoopForUI is often allocated via MessageLoop(TYPE_UI).  Any extra
 // data that you need should be stored on the MessageLoop's pump_ instance.
 COMPILE_ASSERT(sizeof(MessageLoop) == sizeof(MessageLoopForUI),
                MessageLoopForUI_should_not_have_extra_member_variables);
 
 #endif  // !defined(OS_NACL)
 
@@ skipping 72 matching lines @@
 
 // Do not add any member variables to MessageLoopForIO!  This is important b/c
 // MessageLoopForIO is often allocated via MessageLoop(TYPE_IO).  Any extra
 // data that you need should be stored on the MessageLoop's pump_ instance.
 COMPILE_ASSERT(sizeof(MessageLoop) == sizeof(MessageLoopForIO),
                MessageLoopForIO_should_not_have_extra_member_variables);
 
 }  // namespace base
 
 #endif  // BASE_MESSAGE_LOOP_MESSAGE_LOOP_H_