Work in progress: Adds MessagePumpDispatcher::ShouldExit(). This is used to handle the

ash/accelerators/accelerator_dispatcher.cc

 // 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.
 
 #include "ash/accelerators/accelerator_dispatcher.h"
 
 #if defined(USE_X11)
 #include <X11/Xlib.h>
 
 // Xlib defines RootWindow
@@ skipping 72 matching lines @@
         return true;
       accelerator.set_type(aura::TranslatedKeyEvent(event, false).type());
       if (accelerator_controller->Process(accelerator))
         return true;
     }
   }
 
   return nested_dispatcher_->Dispatch(event);
 }
 
+bool AcceleratorDispatcher::ShouldExit() {
+  return nested_dispatcher_->ShouldExit();
+}
+
 }  // namespace ash