Fix HTMLMediaElement so that it doesn't add cues for disabled text tracks.

Source/core/html/track/LoadableTextTrack.cpp

 /*
  * Copyright (C) 2011 Google 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 90 matching lines @@
     m_loader->getNewCues(newCues);
 
     if (!m_cues)
         m_cues = TextTrackCueList::create();    
 
     for (size_t i = 0; i < newCues.size(); ++i) {
         newCues[i]->setTrack(this);
         m_cues->add(newCues[i]);
     }
 
-    if (client())
+    if (mode() != TextTrack::disabledKeyword() && client())
         client()->textTrackAddCues(this, m_cues.get());
 }
 
 void LoadableTextTrack::cueLoadingStarted(TextTrackLoader* loader)
 {
     ASSERT_UNUSED(loader, m_loader == loader);
 }
 
 void LoadableTextTrack::cueLoadingCompleted(TextTrackLoader* loader, bool loadingFailed)
 {
@@ skipping 32 matching lines @@
         if (node == m_trackElement)
             return index;
         ++index;
     }
     ASSERT_NOT_REACHED();
 
     return 0;
 }
 
 } // namespace WebCore
-