x11: Remove MessagePumpObserver.

base/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 75 matching lines @@
 //     MessageLoop::ScopedNestableTaskAllower allow(MessageLoop::current());
 //     hr = DoDragDrop(...); // Implicitly runs a modal message loop.
 //   }
 //   // Process |hr| (the result returned by DoDragDrop()).
 //
 // Please be SURE your task is reentrant (nestable) and all global variables
 // are stable and accessible before calling SetNestableTasksAllowed(true).
 //
 class BASE_EXPORT MessageLoop : public MessagePump::Delegate {
  public:
-
-#if defined(USE_AURA)
+#if defined(OS_WIN)
   typedef MessagePumpObserver Observer;
 #elif defined(USE_GTK_MESSAGE_PUMP)
   typedef MessagePumpGdkObserver Observer;
 #endif
 
   // A MessageLoop has a particular type, which indicates the set of
   // asynchronous events it may process in addition to tasks and timers.
   //
   // TYPE_DEFAULT
   //   This type of ML only supports tasks and timers.
@@ skipping 462 matching lines @@
   void Attach();
 #endif
 
 #if defined(OS_ANDROID)
   // On Android, the UI message loop is handled by Java side. So Run() should
   // never be called. Instead use Start(), which will forward all the native UI
   // events to the Java message loop.
   void Start();
 #endif
 
-#if !defined(OS_NACL) && (defined(TOOLKIT_GTK) || \
-                          defined(OS_WIN) || defined(USE_X11))
-  // Please see message_pump_win/message_pump_glib for definitions of these
-  // methods.
+#if !defined(OS_NACL) && defined(OS_WIN)
+  // Please see message_pump_win for definitions of these methods.
   void AddObserver(Observer* observer);
   void RemoveObserver(Observer* observer);
 #endif
 
 #if defined(USE_OZONE)
   // Please see MessagePumpLibevent for definition.
   bool WatchFileDescriptor(
       int fd,
       bool persistent,
       MessagePumpLibevent::Mode mode,
@@ skipping 123 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_