Remove --ash-enable-tray-dragging flag

ash/wm/gestures/shelf_gesture_handler.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_WM_GESTURES_SHELF_GESTURE_HANDLER_H_
 #define ASH_WM_GESTURES_SHELF_GESTURE_HANDLER_H_
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 
 namespace ui {
 class GestureEvent;
 }
 
 namespace ash {
-class TrayGestureHandler;
 
 // This manages gestures on the shelf (e.g. launcher, status tray) that affects
 // the shelf visibility.
 class ShelfGestureHandler {
  public:
   ShelfGestureHandler();
   virtual ~ShelfGestureHandler();
 
   // Processes a gesture event and updates the status of the shelf when
   // appropriate. Returns true of the gesture has been handled and it should not
   // be processed any farther, false otherwise.
   bool ProcessGestureEvent(const ui::GestureEvent& event);
 
  private:
   bool drag_in_progress_;
 
-  scoped_ptr<TrayGestureHandler> tray_handler_;
-
   DISALLOW_COPY_AND_ASSIGN(ShelfGestureHandler);
 };
 
 }  // namespace ash
 
 #endif  // ASH_WM_GESTURES_SHELF_GESTURE_HANDLER_H_