Add OnDisplayMetricsChanged in DisplayObserver.

ash/display/display_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_DISPLAY_DISPLAY_CONTROLLER_H_
 #define ASH_DISPLAY_DISPLAY_CONTROLLER_H_
 
 #include <map>
 #include <vector>
 
@@ skipping 129 matching lines @@
   gfx::Insets GetOverscanInsets(int64 display_id) const;
   void SetOverscanInsets(int64 display_id, const gfx::Insets& insets_in_dip);
 
   // Checks if the mouse pointer is on one of displays, and moves to
   // the center of the nearest display if it's outside of all displays.
   void EnsurePointerInDisplays();
 
   // Sets the work area's |insets| to the display assigned to |window|.
   bool UpdateWorkAreaOfDisplayNearestWindow(const aura::Window* window,
                                             const gfx::Insets& insets);
-  // aura::DisplayObserver overrides:
-  virtual void OnDisplayBoundsChanged(
-      const gfx::Display& display) OVERRIDE;
+  // gfx::DisplayObserver overrides:
   virtual void OnDisplayAdded(const gfx::Display& display) OVERRIDE;
   virtual void OnDisplayRemoved(const gfx::Display& display) OVERRIDE;
+  virtual void OnDisplayMetricsChanged(const gfx::Display& display,
+                                       uint32_t metrics) OVERRIDE;
 
   // aura::WindowTreeHostObserver overrides:
   virtual void OnHostResized(const aura::WindowTreeHost* host) OVERRIDE;
 
   // aura::DisplayManager::Delegate overrides:
   virtual void CreateOrUpdateNonDesktopDisplay(const DisplayInfo& info)
       OVERRIDE;
   virtual void CloseNonDesktopDisplay() OVERRIDE;
   virtual void PreDisplayConfigurationChange(bool clear_focus) OVERRIDE;
   virtual void PostDisplayConfigurationChange() OVERRIDE;
@@ skipping 55 matching lines @@
   // restore the cursor location when display configuration
   // changed.
   gfx::Point cursor_location_in_native_coords_for_restore_;
 
   DISALLOW_COPY_AND_ASSIGN(DisplayController);
 };
 
 }  // namespace ash
 
 #endif  // ASH_DISPLAY_DISPLAY_CONTROLLER_H_