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

Source/core/html/HTMLMediaElement.cpp

Index: Source/core/html/HTMLMediaElement.cpp
diff --git a/Source/core/html/HTMLMediaElement.cpp b/Source/core/html/HTMLMediaElement.cpp
index 950ce40d78b7d2433f41bfa2887c2031907f8137..7a0f542984a115d6410af0e774966a8cb963861d 100644
--- a/Source/core/html/HTMLMediaElement.cpp
+++ b/Source/core/html/HTMLMediaElement.cpp
@@ -1318,7 +1318,7 @@ void HTMLMediaElement::textTrackRemoveCue(TextTrack*, PassRefPtr<TextTrackCue> c
     m_cueTree.remove(interval);
 
     size_t index = m_currentlyActiveCues.find(interval);
-    if (index != notFound) {
+    if (index != kNotFound) {
         m_currentlyActiveCues.remove(index);
         cue->setIsActive(false);
     }
@@ -2716,7 +2716,7 @@ void HTMLMediaElement::didRemoveTrack(HTMLTrackElement* trackElement)
     removeTrack(textTrack.get());
 
     size_t index = m_textTracksWhenResourceSelectionBegan.find(textTrack.get());
-    if (index != notFound)
+    if (index != kNotFound)
         m_textTracksWhenResourceSelectionBegan.remove(index);
 }