Tweak TextTrackCue/VTTCue virtual functions

Source/core/html/track/TextTrackCue.cpp

 /*
  * Copyright (C) 2011 Google Inc.  All rights reserved.
  * Copyright (C) 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 43 matching lines @@
 TextTrackCue::TextTrackCue(double start, double end)
     : m_startTime(start)
     , m_endTime(end)
     , m_cueIndex(invalidCueIndex)
     , m_track(0)
     , m_isActive(false)
     , m_pauseOnExit(false)
 {
 }
 
-String TextTrackCue::toString() const
-{
-    return String::format("%p id=%s interval=%f-->%f)", this, id().utf8().data(), startTime(), endTime());
-}
-
 void TextTrackCue::cueWillChange()
 {
     if (m_track)
         m_track->cueWillChange(this);
 }
 
 void TextTrackCue::cueDidChange()
 {
     if (m_track)
         m_track->cueDidChange(this);
@@ skipping 94 matching lines @@
     if (!active)
         removeDisplayTree();
 }
 
 const AtomicString& TextTrackCue::interfaceName() const
 {
     return EventTargetNames::TextTrackCue;
 }
 
 } // namespace WebCore