Update from https://crrev.com/309415

base/timer/timer.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.
 
 // OneShotTimer and RepeatingTimer provide a simple timer API.  As the names
 // suggest, OneShotTimer calls you back once after a time delay expires.
 // RepeatingTimer on the other hand calls you back periodically with the
 // prescribed time interval.
 //
 // OneShotTimer and RepeatingTimer both cancel the timer when they go out of
@@ skipping 241 matching lines @@
   typedef void (Receiver::*ReceiverMethod)();
 
   DelayTimer(const tracked_objects::Location& posted_from,
              TimeDelta delay,
              Receiver* receiver,
              ReceiverMethod method)
       : Timer(posted_from, delay,
               base::Bind(method, base::Unretained(receiver)),
               false) {}
 
-  void Reset() { Timer::Reset(); }
+  void Reset() override { Timer::Reset(); }
 };
 
 }  // namespace base
 
 #endif  // BASE_TIMER_TIMER_H_