Remove virtual where not needed in TextTrackCue

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 1190 matching lines @@
 }
 
 Document& TextTrackCue::document() const
 {
     ASSERT(m_cueBackgroundBox);
     return m_cueBackgroundBox->document();
 }
 
 bool TextTrackCue::operator==(const TextTrackCue& cue) const
 {
-    if (cueType() != cue.cueType())
-        return false;
-
     if (m_endTime != cue.endTime())
         return false;
     if (m_startTime != cue.startTime())
         return false;
     if (m_content != cue.text())
         return false;
     if (m_settings != cue.cueSettings())
         return false;
     if (m_id != cue.id())
         return false;
     if (m_textPosition != cue.position())
         return false;
     if (m_linePosition != cue.line())
         return false;
     if (m_cueSize != cue.size())
         return false;
     if (align() != cue.align())
         return false;
 
     return true;
 }
 
 } // namespace WebCore