Removes the space for notification icon if it's not visible (2nd)

ash/system/status_area_widget_delegate.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_SYSTEM_STATUS_AREA_WIDGET_DELEGATE_H_
 #define ASH_SYSTEM_STATUS_AREA_WIDGET_DELEGATE_H_
 
 #include "ash/ash_export.h"
 #include "ash/shelf/shelf_types.h"
 #include "ash/wm/gestures/shelf_gesture_handler.h"
@@ skipping 32 matching lines @@
 
   // Overridden from ui::EventHandler:
   virtual void OnGestureEvent(ui::GestureEvent* event) OVERRIDE;
 
   // views::WidgetDelegate overrides:
   virtual bool CanActivate() const OVERRIDE;
   virtual void DeleteDelegate() OVERRIDE;
 
  protected:
   // Overridden from views::View:
-  virtual void ChildPreferredSizeChanged(View* child) OVERRIDE;
+  virtual void ChildPreferredSizeChanged(views::View* child) OVERRIDE;
+  virtual void ChildVisibilityChanged(views::View* child) OVERRIDE;
 
  private:
   void UpdateWidgetSize();
 
   const FocusCycler* focus_cycler_for_testing_;
   ShelfAlignment alignment_;
 
   ShelfGestureHandler gesture_handler_;
 
   DISALLOW_COPY_AND_ASSIGN(StatusAreaWidgetDelegate);
 };
 
 }  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_SYSTEM_STATUS_AREA_WIDGET_DELEGATE_H_