Remove WebInbandTextTrack::isDefault()

Source/web/InbandTextTrackPrivateImpl.cpp

 /*
  * Copyright (C) 2013 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 56 matching lines @@
 AtomicString InbandTextTrackPrivateImpl::label() const
 {
     return m_track->label();
 }
 
 AtomicString InbandTextTrackPrivateImpl::language() const
 {
     return m_track->language();
 }
 
-bool InbandTextTrackPrivateImpl::isDefault() const
-{
-    return m_track->isDefault();
-}
-
 int InbandTextTrackPrivateImpl::textTrackIndex() const
 {
     return m_track->textTrackIndex();
 }
 
 void InbandTextTrackPrivateImpl::addWebVTTCue(
     double start,
     double end,
     const WebString& id,
     const WebString& content,
     const WebString& settings)
 {
     client()->addWebVTTCue(this, start, end, id, content, settings);
 }
 
 } // namespace WebKit