Render inband text tracks in the media pipeline

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 14 matching lines @@
 class TextTrack {
  public:
   virtual ~TextTrack() {}
   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<scoped_ptr<TextTrack>
+typedef base::Callback<void
+    (scoped_ptr<TextTrack>)> AddTextTrackDoneCB;
+
+typedef base::Callback<void
     (TextKind kind,
      const std::string& label,
-     const std::string& language)> AddTextTrackCB;
+     const std::string& language,
+     const AddTextTrackDoneCB& done_cb)> AddTextTrackCB;
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_TEXT_TRACK_H_