Only 'form associated' elements have a potential form owner.

Source/core/html/HTMLObjectElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Stefan Schimanski (1Stein@gmx.de)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  *
  * 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
@@ skipping 431 matching lines @@
     Widget* widget = pluginWidget();
     if (!widget || !widget->isPluginView())
         return false;
     String value;
     if (!toPluginView(widget)->getFormValue(value))
         return false;
     encoding.appendData(name(), value);
     return true;
 }
 
-HTMLFormElement* HTMLObjectElement::virtualForm() const
+HTMLFormElement* HTMLObjectElement::formOwner() const
 {
     return FormAssociatedElement::form();
 }
 
 bool HTMLObjectElement::isInteractiveContent() const
 {
     return fastHasAttribute(usemapAttr);
 }
 
 bool HTMLObjectElement::useFallbackContent() const
 {
     return HTMLPlugInElement::useFallbackContent() || m_useFallbackContent;
 }
 
 }