Remove some dead code from html/

Source/core/html/MediaController.cpp

 /*
  * Copyright (C) 2011 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 65 matching lines @@
     bringElementUpToSpeed(element);
 }
 
 void MediaController::removeMediaElement(HTMLMediaElement* element)
 {
     ASSERT(element);
     ASSERT(m_mediaElements.contains(element));
     m_mediaElements.remove(m_mediaElements.find(element));
 }
 
-bool MediaController::containsMediaElement(HTMLMediaElement* element) const
-{
-    return m_mediaElements.contains(element);
-}
-
 PassRefPtr<TimeRanges> MediaController::buffered() const
 {
     if (m_mediaElements.isEmpty())
         return TimeRanges::create();
 
     // The buffered attribute must return a new static normalized TimeRanges object that represents
     // the intersection of the ranges of the media resources of the slaved media elements that the
     // user agent has buffered, at the time the attribute is evaluated.
     RefPtr<TimeRanges> bufferedRanges = m_mediaElements.first()->buffered();
     for (size_t index = 1; index < m_mediaElements.size(); ++index)
@@ skipping 537 matching lines @@
 {
     double now = WTF::currentTime();
     double timedelta = now - m_previousTimeupdateTime;
 
     if (timedelta < maxTimeupdateEventFrequency)
         return;
 
     scheduleEvent(EventTypeNames::timeupdate);
     m_previousTimeupdateTime = now;
 }