Remove ash tray utility functions that are no-ops in MD.

ash/common/system/tray/tray_image_item.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_COMMON_SYSTEM_TRAY_TRAY_IMAGE_ITEM_H_
 #define ASH_COMMON_SYSTEM_TRAY_TRAY_IMAGE_ITEM_H_
 
 #include "ash/ash_export.h"
 #include "ash/common/system/tray/system_tray_item.h"
 #include "base/macros.h"
@@ skipping 18 matching lines @@
                 UmaType uma_type);
   ~TrayImageItem() override;
 
   views::View* tray_view();
 
  protected:
   virtual bool GetInitialVisibility() = 0;
 
   // Overridden from SystemTrayItem.
   views::View* CreateTrayView(LoginStatus status) override;
-  views::View* CreateDefaultView(LoginStatus status) override;
-  views::View* CreateDetailedView(LoginStatus status) override;
   void DestroyTrayView() override;
-  void DestroyDefaultView() override;
-  void DestroyDetailedView() override;
-  void UpdateAfterLoginStatusChange(LoginStatus status) override;
-  void UpdateAfterShelfAlignmentChange(ShelfAlignment alignment) override;
 
   // Sets the color of the icon to |color|.
   void SetIconColor(SkColor color);
 
  private:
   // Sets the current icon on |tray_view_|'s ImageView.
   void UpdateImageOnImageView();
 
   // The icon and its current color.
   const gfx::VectorIcon& icon_;
   SkColor icon_color_;
 
   // The image view in the tray.
   TrayItemView* tray_view_;
 
   DISALLOW_COPY_AND_ASSIGN(TrayImageItem);
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_SYSTEM_TRAY_TRAY_IMAGE_ITEM_H_