IDL: Use Nullable for union type return value

Source/core/html/HTMLFormElement.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010 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
  * version 2 of the License, or (at your option) any later version.
@@ skipping 99 matching lines @@
     void finishRequestAutocomplete(AutocompleteResult);
 
     DEFINE_ATTRIBUTE_EVENT_LISTENER(autocomplete);
     DEFINE_ATTRIBUTE_EVENT_LISTENER(autocompleteerror);
 
     RadioButtonGroupScope& radioButtonGroupScope() { return m_radioButtonGroupScope; }
 
     const FormAssociatedElement::List& associatedElements() const;
     const WillBeHeapVector<RawPtrWillBeMember<HTMLImageElement> >& imageElements();
 
-    void anonymousNamedGetter(const AtomicString& name, bool&, RefPtrWillBeRawPtr<RadioNodeList>&, bool&, RefPtrWillBeRawPtr<Element>&);
+    void anonymousNamedGetter(const AtomicString& name, RefPtrWillBeRawPtr<RadioNodeList>&, RefPtrWillBeRawPtr<Element>&);
 
 private:
     explicit HTMLFormElement(Document&);
 
     virtual bool rendererIsNeeded(const RenderStyle&) OVERRIDE;
     virtual InsertionNotificationRequest insertedInto(ContainerNode*) OVERRIDE;
     virtual void removedFrom(ContainerNode*) OVERRIDE;
     virtual void finishParsingChildren() OVERRIDE;
 
     virtual void handleLocalEvents(Event*) OVERRIDE;
@@ skipping 53 matching lines @@
     bool m_isInResetFunction;
 
     bool m_wasDemoted;
 
     OwnPtrWillBeMember<GenericEventQueue> m_pendingAutocompleteEventsQueue;
 };
 
 } // namespace blink
 
 #endif // HTMLFormElement_h