Keep the mouse cursor within desktop

ash/monitor/monitor_change_observer_x11.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 UI_AURA_MONITOR_CHANGE_OBSERVER_H
-#define UI_AURA_MONITOR_CHANGE_OBSERVER_H
+#ifndef ASH_MONITOR_MONITOR_CHANGE_OBSERVER_X11_H
+#define ASH_MONITOR_MONITOR_CHANGE_OBSERVER_X11_H
 #pragma once
 
 #include <X11/Xlib.h>
 
 // Xlib.h defines RootWindow.
 #undef RootWindow
 
 #include "base/basictypes.h"
+#include "base/message_loop.h"
 #include "ui/aura/aura_export.h"
 
-namespace aura {
+namespace ash {
+namespace internal {
 
 // An object that observes changes in monitor configuration and
 // update MonitorManagers.
-class AURA_EXPORT MonitorChangeObserverX11 {
+class MonitorChangeObserverX11 : public MessageLoop::Dispatcher {
  public:
   MonitorChangeObserverX11();
   ~MonitorChangeObserverX11();
 
-  bool Dispatch(const XEvent* event);
+  // Overridden from Dispatcher overrides:
+  virtual base::MessagePumpDispatcher::DispatchStatus Dispatch(
+      XEvent* xev) OVERRIDE;
 
   // Reads monitor configurations from the system and notifies
   // |monitor_manager_| about the change.
   void NotifyMonitorChange();
 
  private:
   Display* xdisplay_;
 
   ::Window x_root_window_;
 
   int xrandr_event_base_;
 
   DISALLOW_COPY_AND_ASSIGN(MonitorChangeObserverX11);
 };
 
+}  // namespace internal
 }  // namespace aura
 
-#endif  // UI_AURA_MONITOR_CHANGE_OBSERVER_H
+#endif  // ASH_MONITOR_MONITOR_CHANGE_OBSERVER_X11_H