Eliminate ash::internal namespace

ash/wm/panels/panel_window_event_handler.h

 // Copyright 2013 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_PANELS_PANEL_WINDOW_EVENT_HANDLER_H_
 #define ASH_WM_PANELS_PANEL_WINDOW_EVENT_HANDLER_H_
 
 #include "ui/events/event_handler.h"
 
 namespace ash {
-namespace internal {
 
 // PanelWindowEventHandler minimizes panels when the user double clicks or
 // double taps on the panel header.
 class PanelWindowEventHandler : public ui::EventHandler {
  public:
   PanelWindowEventHandler();
   virtual ~PanelWindowEventHandler();
 
   // ui::EventHandler:
   virtual void OnMouseEvent(ui::MouseEvent* event) OVERRIDE;
   virtual void OnGestureEvent(ui::GestureEvent* event) OVERRIDE;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(PanelWindowEventHandler);
 };
 
-}  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_WM_PANELS_PANEL_WINDOW_EVENT_HANDLER_H_