Prevent 'removetrack' events from firing when all inband text tracks are removed.

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 183 matching lines @@
 
     ASSERT(!track->trackList());
     track->setTrackList(this);
 
     scheduleAddTrackEvent(track.release());
 }
 
 void TextTrackList::remove(TextTrack* track)
 {
     Vector<RefPtr<TextTrack> >* tracks = 0;
-    RefPtr<InbandTextTrack> inbandTrack;
 
     if (track->trackType() == TextTrack::TrackElement) {
         tracks = &m_elementTracks;
     } else if (track->trackType() == TextTrack::AddTrack) {
         tracks = &m_addTrackTracks;
     } else if (track->trackType() == TextTrack::InBand) {
         tracks = &m_inbandTracks;
-        inbandTrack = static_cast<InbandTextTrack*>(track);
     } else {
         ASSERT_NOT_REACHED();
     }
 
     size_t index = tracks->find(track);
     if (index == kNotFound)
         return;
 
     invalidateTrackIndexesAfterTrack(track);
 
     ASSERT(track->trackList() == this);
     track->setTrackList(0);
 
     tracks->remove(index);
 
-    if (inbandTrack)
-        inbandTrack->trackRemoved();
+    scheduleRemoveTrackEvent(track);
+}
 
-    scheduleRemoveTrackEvent(track);
+void TextTrackList::removeAllInbandTracks()
+{
+    for (unsigned i = 0; i < m_inbandTracks.size(); ++i) {
+        m_inbandTracks[i]->invalidateTrackIndex();
+        m_inbandTracks[i]->setTrackList(0);
+    }
+    m_inbandTracks.clear();
 }
 
 bool TextTrackList::contains(TextTrack* track) const
 {
     const Vector<RefPtr<TextTrack> >* tracks = 0;
 
     if (track->trackType() == TextTrack::TrackElement)
         tracks = &m_elementTracks;
     else if (track->trackType() == TextTrack::AddTrack)
         tracks = &m_addTrackTracks;
@@ skipping 69 matching lines @@
     // media element, then the user agent must remove the track element's
     // corresponding text track from the media element's list of text tracks,
     // and then queue a task to fire a trusted event with the name removetrack,
     // that does not bubble and is not cancelable, and that uses the TrackEvent
     // interface, with the track attribute initialized to the text track's
     // TextTrack object, at the media element's textTracks attribute's
     // TextTrackList object.
     scheduleTrackEvent(EventTypeNames::removetrack, track);
 }
 
-Node* TextTrackList::owner() const
+HTMLMediaElement* TextTrackList::owner() const
 {
     return m_owner;
 }