Make NodeList::ownerNode() virtual and rename to virtualOwnerNode()

Source/core/dom/ChildNodeList.h

Index: Source/core/dom/ChildNodeList.h
diff --git a/Source/core/dom/ChildNodeList.h b/Source/core/dom/ChildNodeList.h
index b356cdfb5616f961da8fb5beae2a5dcca799d121..0fe38cc7abdc24faa58e532c019570c05693df56 100644
--- a/Source/core/dom/ChildNodeList.h
+++ b/Source/core/dom/ChildNodeList.h
@@ -59,6 +59,7 @@ private:
     explicit ChildNodeList(PassRefPtr<ContainerNode> rootNode);
 
     virtual bool isChildNodeList() const OVERRIDE { return true; }
+    virtual Node* virtualOwnerNode() const OVERRIDE;
 
     RefPtr<ContainerNode> m_parent;
     mutable CollectionIndexCache<ChildNodeList, Node> m_collectionIndexCache;