Revert "Fix a ton of compiler warnings."

media/base/clock.h

 // Copyright (c) 2009 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.
 //
 // A clock represent a single source of time to allow audio and video streams
 // to synchronize with each other.  Clocks essentially track the media time with
 // respect to some other source of time, whether that may be the system clock,
 // audio hardware or some other OS-level API.
 //
 // Clocks start off paused with a playback rate of 1.0f and a media time of 0.
@@ skipping 22 matching lines @@
   // Sets a new playback rate.  The rate at which the media time will increase
   // will now change.
   virtual void SetPlaybackRate(float playback_rate) = 0;
 
   // Forcefully sets the media time to the given time.  This should only be used
   // where a discontinuity in the media is found (i.e., seeking).
   virtual void SetTime(const base::TimeDelta& time) = 0;
 
   // Returns the current elapsed media time.
   virtual base::TimeDelta Elapsed() const = 0;
-
- protected:
-  ~Clock() {}
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_CLOCK_H_