wayland: use message_pump_observer common code

base/message_pump_wayland.h

 // Copyright (c) 2011 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_PUMP_WAYLAND_H_
 #define BASE_MESSAGE_PUMP_WAYLAND_H_
 #pragma once
 
 #include "base/memory/scoped_ptr.h"
 #include "base/message_pump_glib.h"
+#include "base/message_pump_observer.h"
 
 typedef struct _GMainContext GMainContext;
 typedef struct _GPollFD GPollFD;
 typedef struct _GSource GSource;
 
 namespace base {
 
 namespace wayland {
 union WaylandEvent;
 }
 
 // The documentation for this class is in message_pump_glib.h
-class BASE_EXPORT MessagePumpObserver {
- public:
-   enum EventStatus {
-     EVENT_CONTINUE,    // The event should be dispatched as normal.
-     EVENT_HANDLED      // The event should not be processed any farther.
-   };
-
-  // This method is called before processing an Event. If the method returns
-  // EVENT_HANDLED, it indicates the event has already been handled, so the
-  // event is not processed any farther. If the method returns EVENT_CONTINUE,
-  // the event dispatching proceeds as normal.
-  virtual EventStatus WillProcessEvent(wayland::WaylandEvent* event);
-
- protected:
-  virtual ~MessagePumpObserver() {}
-};
-
-// The documentation for this class is in message_pump_glib.h
 //
 // The nested loop is exited by either posting a quit, or returning false
 // from Dispatch.
 class MessagePumpDispatcher {
  public:
   enum DispatchStatus {
     EVENT_IGNORED,    // The event was not processed.
     EVENT_PROCESSED,  // The event has been processed.
     EVENT_QUIT        // The event was processed and the message-loop should
                       // terminate.
@@ skipping 21 matching lines @@
   GMainContext* context_;
 
   DISALLOW_COPY_AND_ASSIGN(MessagePumpWayland);
 };
 
 typedef MessagePumpWayland MessagePumpForUI;
 
 }  // namespace base
 
 #endif  // BASE_MESSAGE_PUMP_WAYLAND_H_