Never create HTMLTrackElement when VideoTrack is not enabled

Source/core/html/HTMLMediaElement.cpp

 /*
  * Copyright (C) 2007, 2008, 2009, 2010, 2011, 2012, 2013 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 598 matching lines @@
 
     return canPlay;
 }
 
 void HTMLMediaElement::load()
 {
     RefPtr<HTMLMediaElement> protect(this); // loadInternal may result in a 'beforeload' event, which can make arbitrary DOM mutations.
 
     LOG(Media, "HTMLMediaElement::load()");
 
+    if (document().settings() && !document().settings()->mediaEnabled())
+        return;
+
     if (userGestureRequiredForLoad() && !UserGestureIndicator::processingUserGesture())
         return;
 
     m_loadInitiatedByUserGesture = UserGestureIndicator::processingUserGesture();
     if (m_loadInitiatedByUserGesture)
         removeBehaviorsRestrictionsAfterFirstUserGesture();
     prepareForLoad();
     loadInternal();
     prepareToPlay();
 }
@@ skipping 3239 matching lines @@
 {
     scheduleLayerUpdate();
 }
 
 bool HTMLMediaElement::isInteractiveContent() const
 {
     return fastHasAttribute(controlsAttr);
 }
 
 }