Move DIP translation from ui/aura to ui/compositor

ash/monitor/multi_monitor_manager.h

Index: ash/monitor/multi_monitor_manager.h
diff --git a/ash/monitor/multi_monitor_manager.h b/ash/monitor/multi_monitor_manager.h
index 6ecd8a799934e28a25b24506a2f518246cd4d554..3d8a76b5c5f68abb4b03d766eabf33cfb4ab699b 100644
--- a/ash/monitor/multi_monitor_manager.h
+++ b/ash/monitor/multi_monitor_manager.h
@@ -37,6 +37,7 @@ class ASH_EXPORT MultiMonitorManager : public aura::MonitorManager,
   // of on a device.
   static void AddRemoveMonitor();
   static void CycleMonitor();
+  static void ToggleMonitorScale();
 
   bool UpdateWorkAreaOfMonitorNearestWindow(const aura::Window* window,
                                             const gfx::Insets& insets);
@@ -64,6 +65,7 @@ class ASH_EXPORT MultiMonitorManager : public aura::MonitorManager,
   void Init();
   void AddRemoveMonitorImpl();
   void CycleMonitorImpl();
+  void ScaleMonitorImpl();
   gfx::Monitor& FindMonitorById(int id);
 
   Monitors monitors_;