WTF::notFound looks too much like a local variable.

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 1300 matching lines @@
 void HTMLMediaElement::textTrackRemoveCue(TextTrack*, PassRefPtr<TextTrackCue> cue)
 {
     // Negative duration cues need to be treated in the interval tree as
     // zero-length cues.
     double endTime = max(cue->startTime(), cue->endTime());
 
     CueInterval interval = m_cueTree.createInterval(cue->startTime(), endTime, cue.get());
     m_cueTree.remove(interval);
 
     size_t index = m_currentlyActiveCues.find(interval);
-    if (index != notFound) {
+    if (index != kNotFound) {
         m_currentlyActiveCues.remove(index);
         cue->setIsActive(false);
     }
 
     cue->removeDisplayTree();
     updateActiveTextTrackCues(currentTime());
 }
 
 
 bool HTMLMediaElement::isSafeToLoadURL(const KURL& url, InvalidURLAction actionIfInvalid)
@@ skipping 1377 matching lines @@
     if (!m_textTracks)
         return;
 
     // 4.8.10.12.3 Sourcing out-of-band text tracks
     // When a track element's parent element changes and the old parent was a media element,
     // then the user agent must remove the track element's corresponding text track from the
     // media element's list of text tracks.
     removeTrack(textTrack.get());
 
     size_t index = m_textTracksWhenResourceSelectionBegan.find(textTrack.get());
-    if (index != notFound)
+    if (index != kNotFound)
         m_textTracksWhenResourceSelectionBegan.remove(index);
 }
 
 static int textTrackLanguageSelectionScore(const TextTrack& track)
 {
     if (track.language().isEmpty())
         return 0;
 
     Vector<String> languages = userPreferredLanguages();
     size_t languageMatchIndex = indexOfBestMatchingLanguageInList(track.language(), languages);
@@ skipping 1266 matching lines @@
 {
     m_restrictions = NoRestrictions;
 }
 
 void HTMLMediaElement::mediaPlayerScheduleLayerUpdate()
 {
     scheduleLayerUpdate();
 }
 
 }