Do not use inbandTrackIndex() when assigning track index

Source/core/html/track/TextTrackList.cpp

 /*
  * Copyright (C) 2011, 2012 Apple Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 176 matching lines @@
 {
     RefPtrWillBeRawPtr<TextTrack> track = prpTrack;
 
     if (track->trackType() == TextTrack::AddTrack) {
         m_addTrackTracks.append(track);
     } else if (track->trackType() == TextTrack::TrackElement) {
         // Insert tracks added for <track> element in tree order.
         size_t index = static_cast<LoadableTextTrack*>(track.get())->trackElementIndex();
         m_elementTracks.insert(index, track);
     } else if (track->trackType() == TextTrack::InBand) {
-        // Insert tracks added for in-band in the media file order.
-        size_t index = static_cast<InbandTextTrack*>(track.get())->inbandTrackIndex();
-        m_inbandTracks.insert(index, track);
+        m_inbandTracks.append(track);
     } else {
         ASSERT_NOT_REACHED();
     }
 
     invalidateTrackIndexesAfterTrack(track.get());
 
     ASSERT(!track->trackList());
     track->setTrackList(this);
 
     scheduleAddTrackEvent(track.release());
@@ skipping 123 matching lines @@
 
 void TextTrackList::trace(Visitor* visitor)
 {
     visitor->trace(m_owner);
     visitor->trace(m_asyncEventQueue);
     visitor->trace(m_addTrackTracks);
     visitor->trace(m_elementTracks);
     visitor->trace(m_inbandTracks);
     EventTargetWithInlineData::trace(visitor);
 }