Revert 212948 "Made MessagePump a non-thread safe class."

trunk/src/base/message_loop/message_pump_gtk.h

 // Copyright (c) 2012 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_PUMP_GTK_H_
 #define BASE_MESSAGE_LOOP_MESSAGE_PUMP_GTK_H_
 
 #include "base/message_loop/message_pump_glib.h"
 
 typedef union _GdkEvent GdkEvent;
@@ skipping 25 matching lines @@
   virtual bool Dispatch(GdkEvent* event) = 0;
 
  protected:
   virtual ~MessagePumpDispatcher() {}
 };
 
 // This class implements a message-pump for dispatching GTK events.
 class BASE_EXPORT MessagePumpGtk : public MessagePumpGlib {
  public:
   MessagePumpGtk();
-  virtual ~MessagePumpGtk();
 
   // Dispatch an available GdkEvent. Essentially this allows a subclass to do
   // some task before/after calling the default handler (EventDispatcher).
   void DispatchEvents(GdkEvent* event);
 
   // Returns default X Display.
   static Display* GetDefaultXDisplay();
 
+ protected:
+  virtual ~MessagePumpGtk();
+
  private:
   // Invoked from EventDispatcher. Notifies all observers we're about to
   // process an event.
   void WillProcessEvent(GdkEvent* event);
 
   // Invoked from EventDispatcher. Notifies all observers we processed an
   // event.
   void DidProcessEvent(GdkEvent* event);
 
   // Callback prior to gdk dispatching an event.
   static void EventDispatcher(GdkEvent* event, void* data);
 
   DISALLOW_COPY_AND_ASSIGN(MessagePumpGtk);
 };
 
 typedef MessagePumpGtk MessagePumpForUI;
 
 }  // namespace base
 
 #endif  // BASE_MESSAGE_LOOP_MESSAGE_PUMP_GTK_H_