mash: Migrate some misc ShelfLayoutManager deps to ash common.

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/shelf_icon_observer.h"
 #include "ash/common/shelf/wm_shelf.h"
 #include "ash/shelf/shelf_layout_manager_observer.h"
 #include "base/macros.h"
 #include "base/observer_list.h"
 
 namespace ash {
 
 class Shelf;
+class ShelfBezelEventHandler;
 class ShelfLayoutManager;
 
 // Aura implementation of WmShelf.
 class ASH_EXPORT WmShelfAura : public WmShelf,
                                public ShelfLayoutManagerObserver,
                                public ShelfIconObserver {
  public:
   WmShelfAura();
   ~WmShelfAura() override;
 
@@ skipping 50 matching lines @@
 
   // 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;
 
   base::ObserverList<WmShelfObserver> observers_;
 
   // Forwards mouse and gesture events to ShelfLayoutManager for auto-hide.
+  // TODO(mash): Facilitate simliar functionality in mash: crbug.com/631216
   std::unique_ptr<AutoHideEventHandler> auto_hide_event_handler_;
 
+  // Forwards touch gestures on a bezel sensor to the shelf.
+  // TODO(mash): Facilitate simliar functionality in mash: crbug.com/636647
+  std::unique_ptr<ShelfBezelEventHandler> bezel_event_handler_;
+
   DISALLOW_COPY_AND_ASSIGN(WmShelfAura);
 };
 
 }  // namespace ash
 
 #endif  // ASH_AURA_WM_SHELF_AURA_H_