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

Source/modules/mediasource/SourceBufferList.h

 /*
  * Copyright (C) 2013 Google 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.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 36 matching lines @@
     {
         return adoptRef(new SourceBufferList(context, asyncEventQueue));
     }
     virtual ~SourceBufferList();
 
     unsigned long length() const { return m_list.size(); }
     SourceBuffer* item(unsigned long index) const { return (index < m_list.size()) ? m_list[index].get() : 0; }
 
     void add(PassRefPtr<SourceBuffer>);
     void remove(SourceBuffer*);
-    bool contains(SourceBuffer* buffer) { return m_list.find(buffer) != notFound; }
+    bool contains(SourceBuffer* buffer) { return m_list.find(buffer) != kNotFound; }
     void clear();
 
     // EventTarget interface
     virtual const AtomicString& interfaceName() const OVERRIDE;
     virtual ScriptExecutionContext* scriptExecutionContext() const OVERRIDE;
 
     using RefCounted<SourceBufferList>::ref;
     using RefCounted<SourceBufferList>::deref;
 
 protected:
@@ skipping 11 matching lines @@
     EventTargetData m_eventTargetData;
     ScriptExecutionContext* m_scriptExecutionContext;
     GenericEventQueue* m_asyncEventQueue;
 
     Vector<RefPtr<SourceBuffer> > m_list;
 };
 
 } // namespace WebCore
 
 #endif