C++11 override style change for athena

athena/system/time_view.h

 // Copyright 2014 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 ATHENA_SYSTEM_TIME_VIEW_H_
 #define ATHENA_SYSTEM_TIME_VIEW_H_
 
 #include "athena/system/public/system_ui.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
 #include "ui/views/controls/label.h"
 
 namespace athena {
 
 // View which displays the current time.
 class TimeView : public views::Label {
  public:
   explicit TimeView(SystemUI::ColorScheme color_scheme);
-  virtual ~TimeView();
+  ~TimeView() override;
 
  private:
   // Starts |timer_| to schedule the next update.
   void SetTimer(base::Time now);
 
   // Updates the current time.
   void UpdateText();
 
   base::OneShotTimer<TimeView> timer_;
 
   DISALLOW_COPY_AND_ASSIGN(TimeView);
 };
 
 }  // namespace athena
 
 #endif  // ATHENA_SYSTEM_TIME_VIEW_H_