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

Source/core/dom/LiveNodeList.h

Index: Source/core/dom/LiveNodeList.h
diff --git a/Source/core/dom/LiveNodeList.h b/Source/core/dom/LiveNodeList.h
index bdc6e64e650328080aa1907ba2df083bc873f23a..c819db15357c6957c22186643753ead2a5cd6fce 100644
--- a/Source/core/dom/LiveNodeList.h
+++ b/Source/core/dom/LiveNodeList.h
@@ -45,7 +45,9 @@ public:
     virtual Node* item(unsigned offset) const OVERRIDE FINAL { return m_collectionIndexCache.nodeAt(*this, offset); }
     virtual bool elementMatches(const Element&) const = 0;
 
-    virtual void invalidateCache(Document* oldDocument) const OVERRIDE FINAL;
+    virtual void invalidateCache(Document* oldDocument = 0) const OVERRIDE FINAL;
+    void invalidateCacheForAttribute(const QualifiedName*) const;
+
     bool shouldOnlyIncludeDirectChildren() const { return false; }
 
     // Collection IndexCache API.
@@ -61,6 +63,14 @@ private:
     mutable CollectionIndexCache<LiveNodeList, Element> m_collectionIndexCache;
 };
 
+DEFINE_TYPE_CASTS(LiveNodeList, LiveNodeListBase, list, isLiveNodeListType(list->type()), isLiveNodeListType(list.type()));
+
+inline void LiveNodeList::invalidateCacheForAttribute(const QualifiedName* attrName) const
+{
+    if (!attrName || shouldInvalidateTypeOnAttributeChange(invalidationType(), *attrName))
+        invalidateCache();
+}
+
 } // namespace WebCore
 
 #endif // LiveNodeList_h