Remove Attr child nodes (making Attr a Node, not a ContainerNode)

Source/core/dom/Attribute.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Peter Kelly (pmk@post.com)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2008, 2012 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 11 matching lines @@
  *
  */
 
 #ifndef Attribute_h
 #define Attribute_h
 
 #include "core/dom/QualifiedName.h"
 
 namespace blink {
 
-// This has no counterpart in DOM.
-// It is an internal representation of the node value of an Attr.
-// The actual Attr with its value as a Text child is allocated only if needed.
+// This is the internal representation of an attribute, consisting of a name and
+// value. It is distinct from the web-exposed Attr, which also knows of the
+// element to which it attached, if any.
 class Attribute {
 public:
     Attribute(const QualifiedName& name, const AtomicString& value)
         : m_name(name)
         , m_value(value)
     {
     }
 
     // NOTE: The references returned by these functions are only valid for as long
     // as the Attribute stays in place. For example, calling a function that mutates
@@ skipping 29 matching lines @@
 inline bool Attribute::matches(const QualifiedName& qualifiedName) const
 {
     if (qualifiedName.localName() != localName())
         return false;
     return qualifiedName.prefix() == starAtom || qualifiedName.namespaceURI() == namespaceURI();
 }
 
 } // namespace blink
 
 #endif // Attribute_h