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

Source/core/html/track/TextTrackList.cpp

 /*
  * Copyright (C) 2011, 2012 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 133 matching lines @@
     } else if (track->trackType() == TextTrack::AddTrack) {
         tracks = &m_addTrackTracks;
         for (size_t i = 0; i < m_inbandTracks.size(); ++i)
             m_inbandTracks[i]->invalidateTrackIndex();
     } else if (track->trackType() == TextTrack::InBand)
         tracks = &m_inbandTracks;
     else
         ASSERT_NOT_REACHED();
 
     size_t index = tracks->find(track);
-    if (index == notFound)
+    if (index == kNotFound)
         return;
 
     for (size_t i = index; i < tracks->size(); ++i)
         tracks->at(index)->invalidateTrackIndex();
 }
 
 void TextTrackList::append(PassRefPtr<TextTrack> prpTrack)
 {
     RefPtr<TextTrack> track = prpTrack;
 
@@ skipping 28 matching lines @@
     } else if (track->trackType() == TextTrack::AddTrack) {
         tracks = &m_addTrackTracks;
     } else if (track->trackType() == TextTrack::InBand) {
         tracks = &m_inbandTracks;
         inbandTrack = static_cast<InbandTextTrack*>(track);
     } else {
         ASSERT_NOT_REACHED();
     }
 
     size_t index = tracks->find(track);
-    if (index == notFound)
+    if (index == kNotFound)
         return;
 
     invalidateTrackIndexesAfterTrack(track);
 
     ASSERT(track->mediaElement() == m_owner);
     track->setMediaElement(0);
 
     tracks->remove(index);
 
     if (inbandTrack)
         inbandTrack->trackRemoved();
 }
 
 bool TextTrackList::contains(TextTrack* track) const
 {
     const Vector<RefPtr<TextTrack> >* tracks = 0;
 
     if (track->trackType() == TextTrack::TrackElement)
         tracks = &m_elementTracks;
     else if (track->trackType() == TextTrack::AddTrack)
         tracks = &m_addTrackTracks;
     else if (track->trackType() == TextTrack::InBand)
         tracks = &m_inbandTracks;
     else
         ASSERT_NOT_REACHED();
 
-    return tracks->find(track) != notFound;
+    return tracks->find(track) != kNotFound;
 }
 
 const AtomicString& TextTrackList::interfaceName() const
 {
     return eventNames().interfaceForTextTrackList;
 }
 
 void TextTrackList::scheduleAddTrackEvent(PassRefPtr<TextTrack> track)
 {
     // 4.8.10.12.3 Sourcing out-of-band text tracks
@@ skipping 23 matching lines @@
     size_t count = pendingEvents.size();
     for (size_t index = 0; index < count; ++index)
         dispatchEvent(pendingEvents[index].release(), IGNORE_EXCEPTION);
     --m_dispatchingEvents;
 }
 
 Node* TextTrackList::owner() const
 {
     return m_owner;
 }