mash: Migrate ShelfButton* to wm common types

ash/aura/wm_shelf_aura.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_AURA_WM_SHELF_AURA_H_
 #define ASH_AURA_WM_SHELF_AURA_H_
 
 #include "ash/ash_export.h"
 #include "ash/common/shelf/wm_shelf.h"
 #include "ash/shelf/shelf_icon_observer.h"
@@ skipping 47 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;
 
   // ShelfLayoutManagerObserver:
   void WillDeleteShelfLayoutManager() override;
   void OnAutoHideStateChanged(ShelfAutoHideState new_state) override;
   void OnBackgroundUpdated(ShelfBackgroundType background_type,
                            BackgroundAnimatorChangeType change_type) override;
   void WillChangeVisibilityState(ShelfVisibilityState new_state) override;
 
   // ShelfIconObserver:
   void OnShelfIconPositionsChanged() override;
 
   // May be null during login and during initialization of a secondary display.
   Shelf* shelf_ = nullptr;
 
   // Cached separately because it may be destroyed before |shelf_|.
   ShelfLayoutManager* shelf_layout_manager_ = nullptr;
 
   // Handler for swipe and drag gestures.
   ShelfGestureHandler gesture_handler_;
 
   base::ObserverList<WmShelfObserver> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(WmShelfAura);
 };
 
 }  // namespace ash
 
 #endif  // ASH_AURA_WM_SHELF_AURA_H_