Move Pipeline permanent callbacks into Pipeline::Client interface.

media/base/text_track.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.
 
 #ifndef MEDIA_BASE_TEXT_TRACK_H_
 #define MEDIA_BASE_TEXT_TRACK_H_
 
 #include <string>
 
 #include "base/callback.h"
@@ skipping 10 matching lines @@
   virtual void addWebVTTCue(const base::TimeDelta& start,
                             const base::TimeDelta& end,
                             const std::string& id,
                             const std::string& content,
                             const std::string& settings) = 0;
 };
 
 typedef base::Callback<void
     (scoped_ptr<TextTrack>)> AddTextTrackDoneCB;
 
+// TODO(alokp): Remove.
 typedef base::Callback<void
     (const TextTrackConfig& config,
      const AddTextTrackDoneCB& done_cb)> AddTextTrackCB;
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_TEXT_TRACK_H_