Move views::Accelerator to ui in order to use it from aura code.

chrome/browser/ui/views/critical_notification_bubble_view.h

 // Copyright (c) 2011 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 CHROME_BROWSER_UI_VIEWS_CRITICAL_NOTIFICATION_BUBBLE_VIEW_H_
 #define CHROME_BROWSER_UI_VIEWS_CRITICAL_NOTIFICATION_BUBBLE_VIEW_H_
 #pragma once
 
 #include "base/timer.h"
 #include "views/controls/button/button.h"
 #include "views/bubble/bubble_delegate.h"
 
+namespace ui {
+class Accelerator;
+}
+
 namespace views {
 class Label;
 class NativeTextButton;
 }
 
 class CriticalNotificationBubbleView : public views::BubbleDelegateView,
                                        public views::ButtonListener {
  public:
   explicit CriticalNotificationBubbleView(views::View* anchor_view);
   virtual ~CriticalNotificationBubbleView();
 
   // views::ButtonListener overrides:
   virtual void ButtonPressed(views::Button* sender,
                              const views::Event& event) OVERRIDE;
 
   // views::WidgetDelegate overrides:
   virtual void WindowClosing() OVERRIDE;
 
  protected:
   // views::BubbleDelegateView overrides:
   virtual bool AcceleratorPressed(
-      const views::Accelerator& accelerator) OVERRIDE;
+      const ui::Accelerator& accelerator) OVERRIDE;
   virtual void Init() OVERRIDE;
 
  private:
   // Helper function to calculate the remaining time (in seconds) until
   // spontaneous reboot.
   int GetRemainingTime();
 
   // Helper function to set the headline for the bubble.
   void UpdateBubbleHeadline(int seconds);
 
   // Called when the timer fires each time the clock ticks.
   void OnCountdown();
 
   // The headline and buttons on the bubble.
   views::Label* headline_;
   views::NativeTextButton* restart_button_;
   views::NativeTextButton* dismiss_button_;
 
   // A timer to refresh the bubble to show new countdown value.
   base::RepeatingTimer<CriticalNotificationBubbleView> refresh_timer_;
 
   // When the bubble was created.
   base::Time bubble_created_;
 
   DISALLOW_COPY_AND_ASSIGN(CriticalNotificationBubbleView);
 };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_CRITICAL_NOTIFICATION_BUBBLE_VIEW_H_