chromeos: Fix shelf appearing at login screen under mash

ash/common/shelf/shelf_widget.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_SHELF_SHELF_WIDGET_H_
 #define ASH_COMMON_SHELF_SHELF_WIDGET_H_
 
 #include <memory>
 
 #include "ash/ash_export.h"
@@ skipping 42 matching lines @@
   // is true. The |animation_time_ms| will be used as animation duration.
   void HideShelfBehindBlackBar(bool hide, int animation_time_ms);
   bool IsShelfHiddenBehindBlackBar() const;
 
   ShelfLayoutManager* shelf_layout_manager() { return shelf_layout_manager_; }
   StatusAreaWidget* status_area_widget() const { return status_area_widget_; }
 
   ShelfView* CreateShelfView();
   void PostCreateShelf();
 
-  // Set visibility of the shelf.
-  void SetShelfVisibility(bool visible);
   bool IsShelfVisible() const;
 
   bool IsShowingAppList() const;
   bool IsShowingContextMenu() const;
   bool IsShowingOverflowBubble() const;
 
   // Sets the focus cycler.  Also adds the shelf to the cycle.
   void SetFocusCycler(FocusCycler* focus_cycler);
   FocusCycler* GetFocusCycler();
 
@@ skipping 44 matching lines @@
   ShelfView* shelf_view_;
   ShelfBackgroundAnimator background_animator_;
   bool activating_as_fallback_;
 
   DISALLOW_COPY_AND_ASSIGN(ShelfWidget);
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_SHELF_SHELF_WIDGET_H_