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

ui/aura/single_monitor_manager.h

Index: ui/aura/single_monitor_manager.h
diff --git a/ui/aura/single_monitor_manager.h b/ui/aura/single_monitor_manager.h
index 85dfffa61e66f5b887e70dc1dcf524d25b8cac16..d17ef8f34b17863fc6f87d8a310430ae46f675ef 100644
--- a/ui/aura/single_monitor_manager.h
+++ b/ui/aura/single_monitor_manager.h
@@ -13,6 +13,7 @@
 #include "ui/aura/window_observer.h"
 
 namespace gfx {
+class Monitor;
 class Rect;
 }
 
@@ -27,16 +28,18 @@ class AURA_EXPORT SingleMonitorManager : public MonitorManager,
 
   // MonitorManager overrides:
   virtual void OnNativeMonitorsChanged(
-      const std::vector<const Monitor*>& monitors) OVERRIDE;
+      const std::vector<const gfx::Monitor*>& monitors) OVERRIDE;
   virtual RootWindow* CreateRootWindowForMonitor(
-      Monitor* monitor) OVERRIDE;
-  virtual const Monitor* GetMonitorNearestWindow(
+      gfx::Monitor* monitor) OVERRIDE;
+  virtual gfx::Monitor* GetMonitorAt(size_t index) OVERRIDE;
+
+  virtual size_t GetNumMonitors() const OVERRIDE;
+
+  virtual const gfx::Monitor* GetMonitorNearestWindow(
       const Window* window) const OVERRIDE;
-  virtual const Monitor* GetMonitorNearestPoint(
+  virtual gfx::Monitor* GetMonitorNearestWindow(const Window* window) OVERRIDE;
+  virtual const gfx::Monitor* GetMonitorNearestPoint(
       const gfx::Point& point) const OVERRIDE;
-  virtual Monitor* GetMonitorAt(size_t index) OVERRIDE;
-  virtual size_t GetNumMonitors() const OVERRIDE;
-  virtual Monitor* GetMonitorNearestWindow(const Window* window) OVERRIDE;
 
   // WindowObserver overrides:
   virtual void OnWindowBoundsChanged(Window* window,
@@ -48,7 +51,7 @@ class AURA_EXPORT SingleMonitorManager : public MonitorManager,
   void Update(const gfx::Size size);
 
   RootWindow* root_window_;
-  scoped_ptr<Monitor> monitor_;
+  scoped_ptr<gfx::Monitor> monitor_;
 
   DISALLOW_COPY_AND_ASSIGN(SingleMonitorManager);
 };