Support union return type for anonymous named/indexed getter

Source/core/html/HTMLFormControlsCollection.cpp

Index: Source/core/html/HTMLFormControlsCollection.cpp
diff --git a/Source/core/html/HTMLFormControlsCollection.cpp b/Source/core/html/HTMLFormControlsCollection.cpp
index e4d0793c56614d37296b218aabdd6aea06a85144..e2bf78aee70e1292ee3defb85a2cfd556078eb3a 100644
--- a/Source/core/html/HTMLFormControlsCollection.cpp
+++ b/Source/core/html/HTMLFormControlsCollection.cpp
@@ -161,4 +161,18 @@ void HTMLFormControlsCollection::updateNameCache() const
     setHasNameCache();
 }
 
+WTF::UnionType2<RadioNodeList, Node> HTMLFormControlsCollection::namedGetter(const AtomicString& name)
+{
+    Vector<RefPtr<Node> > namedItems;
+    this->namedItems(name, namedItems);
+
+    if (!namedItems.size())
+        return WTF::UnionType2<RadioNodeList, Node>();
+
+    if (namedItems.size() == 1)
+        return WTF::UnionType2<RadioNodeList, Node>(namedItems.at(0).release());
+
+    return WTF::UnionType2<RadioNodeList, Node>(this->ownerNode()->radioNodeList(name));
+}
+
 }