Update {virtual,override,final} to follow C++11 style in components, round 2.

components/timers/rtc_alarm.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 COMPONENTS_TIMER_RTC_ALARM_H_
 #define COMPONENTS_TIMER_RTC_ALARM_H_
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 30 matching lines @@
   bool Init(base::WeakPtr<AlarmTimer> timer) override;
   void Stop() override;
   void Reset(base::TimeDelta delay) override;
 
   // base::MessageLoopForIO::Watcher overrides.
   void OnFileCanReadWithoutBlocking(int fd) override;
   void OnFileCanWriteWithoutBlocking(int fd) override;
 
  protected:
   // Needs to be protected because AlarmTimer::Delegate is a refcounted class.
-  virtual ~RtcAlarm();
+  ~RtcAlarm() override;
 
  private:
   // Actually performs the system calls to set up the timer.  This must be
   // called on a MessageLoopForIO.
   void ResetImpl(base::TimeDelta delay, int event_id);
 
   // Callback that is run when the timer fires.  Must be run on
   // |origin_message_loop_|.
   void OnTimerFired(int event_id);
 
@@ skipping 24 matching lines @@
   // where the user resets the timer on the original thread, while the event is
   // being fired on the IO thread at the same time.
   int origin_event_id_;
   int io_event_id_;
 
   DISALLOW_COPY_AND_ASSIGN(RtcAlarm);
 };
 
 }  // namespace timers
 #endif  // COMPONENTS_TIMER_RTC_ALARM_H_