LiveNodeListBase code should not need to worry about id/name cache invalidation

Source/core/html/HTMLCollection.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2014 Samsung Electronics. 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
  * version 2 of the License, or (at your option) any later version.
@@ skipping 25 matching lines @@
 class HTMLCollection : public ScriptWrappable, public RefCounted<HTMLCollection>, public LiveNodeListBase {
 public:
     enum ItemAfterOverrideType {
         OverridesItemAfter,
         DoesNotOverrideItemAfter,
     };
 
     static PassRefPtr<HTMLCollection> create(ContainerNode& base, CollectionType);
     virtual ~HTMLCollection();
     virtual void invalidateCache(Document* oldDocument = 0) const OVERRIDE;
+    void invalidateCacheForAttribute(const QualifiedName*) const;
 
     // DOM API
     unsigned length() const { return m_collectionIndexCache.nodeCount(*this); }
     Element* item(unsigned offset) const { return m_collectionIndexCache.nodeAt(*this, offset); }
     virtual Element* namedItem(const AtomicString& name) const;
     bool namedPropertyQuery(const AtomicString&, ExceptionState&);
     void namedPropertyEnumerator(Vector<String>& names, ExceptionState&);
 
     // Non-DOM API
     void namedItems(const AtomicString& name, Vector<RefPtr<Element> >&) const;
@@ skipping 77 matching lines @@
     void unregisterIdNameCacheFromDocument(Document& document) const
     {
         ASSERT(hasValidIdNameCache());
         document.decrementNodeListWithIdNameCacheCount();
     }
 
     const unsigned m_overridesItemAfter : 1;
     const unsigned m_shouldOnlyIncludeDirectChildren : 1;
     mutable OwnPtr<NamedItemCache> m_namedItemCache;
     mutable CollectionIndexCache<HTMLCollection, Element> m_collectionIndexCache;
+};
 
-    friend class LiveNodeListBase;
-};
+DEFINE_TYPE_CASTS(HTMLCollection, LiveNodeListBase, collection, isHTMLCollectionType(collection->type()), isHTMLCollectionType(collection.type()));
+
+inline void HTMLCollection::invalidateCacheForAttribute(const QualifiedName* attrName) const
+{
+    if (!attrName || shouldInvalidateTypeOnAttributeChange(invalidationType(), *attrName))
+        invalidateCache();
+    else if (*attrName == HTMLNames::idAttr || *attrName == HTMLNames::nameAttr)
+        invalidateIdNameCacheMaps();
+}
 
 } // namespace
 
 #endif