Refactor screen/monitor so that gfx::Screen returns monitor object.

ash/monitor/monitor_controller.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 ASH_MONITOR_MONITOR_CONTROLLER_H_
 #define ASH_MONITOR_MONITOR_CONTROLLER_H_
 #pragma once
 
 #include <map>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "ui/aura/monitor_manager.h"
+#include "ui/aura/monitor_observer.h"
 
 namespace aura {
+class Monitor;
 class RootWindow;
 }
 
 namespace ash {
 namespace internal {
 
 // MonitorController creates and maintains RootWindows for each
 // attached monitor, keeping them in sync with monitor configuration changes.
 class MonitorController : public aura::MonitorObserver {
  public:
   MonitorController();
   virtual ~MonitorController();
 
   // aura::MonitorObserver overrides:
-  virtual void OnMonitorBoundsChanged(const aura::Monitor* monitor) OVERRIDE;
-  virtual void OnMonitorAdded(aura::Monitor* monitor) OVERRIDE;
-  virtual void OnMonitorRemoved(const aura::Monitor* monitor) OVERRIDE;
+  virtual void OnMonitorBoundsChanged(
+      const gfx::Monitor& monitor) OVERRIDE;
+  virtual void OnMonitorAdded(const gfx::Monitor& monitor) OVERRIDE;
+  virtual void OnMonitorRemoved(const gfx::Monitor& monitor) OVERRIDE;
 
  private:
   void Init();
 
-  std::map<const aura::Monitor*, aura::RootWindow*> root_windows_;
+  std::map<int, aura::RootWindow*> root_windows_;
 
   DISALLOW_COPY_AND_ASSIGN(MonitorController);
 };
 
 }  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_MONITOR_MONITOR_CONTROLLER_H_