mash: Migrate ShelfButton* to wm common types

ash/mus/bridge/wm_shelf_mus.h

 // Copyright 2016 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_MUS_BRIDGE_WM_SHELF_MUS_H_
 #define ASH_MUS_BRIDGE_WM_SHELF_MUS_H_
 
 #include <stdint.h>
 
 #include <vector>
@@ skipping 33 matching lines @@
   void UpdateIconPositionForWindow(WmWindow* window) override;
   gfx::Rect GetScreenBoundsOfItemIconForWindow(WmWindow* window) override;
   bool ProcessGestureEvent(const ui::GestureEvent& event,
                            WmWindow* target_window) override;
   void UpdateAutoHideForMouseEvent(ui::MouseEvent* event) override;
   void UpdateAutoHideForGestureEvent(ui::GestureEvent* event) override;
   void AddObserver(WmShelfObserver* observer) override;
   void RemoveObserver(WmShelfObserver* observer) override;
   void SetKeyboardBoundsForTesting(const gfx::Rect& bounds) override;
   ShelfLockingManager* GetShelfLockingManagerForTesting() override;
+  ShelfView* GetShelfViewForTesting() override;
 
  private:
   base::ObserverList<WmShelfObserver> observers_;
 
   ShelfLayoutManager* shelf_layout_manager_;
 
   DISALLOW_COPY_AND_ASSIGN(WmShelfMus);
 };
 
 }  // namespace mus
 }  // namespace ash
 
 #endif  // ASH_MUS_BRIDGE_WM_SHELF_MUS_H_