[oilpan] Completely move HTMLFormControlElement's hierarchy to the managed heap

Source/core/html/HTMLFormControlElement.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 12 matching lines @@
 
 #ifndef HTMLFormControlElement_h
 #define HTMLFormControlElement_h
 
 #include "core/html/FormAssociatedElement.h"
 #include "core/html/LabelableElement.h"
 
 namespace WebCore {
 
 class FormDataList;
-class HTMLFieldSetElement;
 class HTMLFormElement;
 class HTMLLegendElement;
 class ValidationMessage;
 class ValidityState;
 
 // HTMLFormControlElement is the default implementation of FormAssociatedElement,
 // and form-associated element implementations should use HTMLFormControlElement
 // unless there is a special reason.
 class HTMLFormControlElement : public LabelableElement, public FormAssociatedElement {
 public:
@@ skipping 48 matching lines @@
     // This must be called when a validation constraint or control value is changed.
     void setNeedsValidityCheck();
     virtual void setCustomValidity(const String&) OVERRIDE;
 
     bool isReadOnly() const { return m_isReadOnly; }
     bool isDisabledOrReadOnly() const { return isDisabledFormControl() || m_isReadOnly; }
 
     bool hasAutofocused() { return m_hasAutofocused; }
     void setAutofocused() { m_hasAutofocused = true; }
 
-    static HTMLFormControlElement* enclosingFormControlElement(Node*);
+    static Result<HTMLFormControlElement> enclosingFormControlElement(Node*);
 
     using Node::ref;
     using Node::deref;
 
     virtual void reportMemoryUsage(MemoryObjectInfo*) const OVERRIDE;
 
+    virtual void acceptHeapVisitor(Visitor*) const OVERRIDE;
+
 protected:
     HTMLFormControlElement(const QualifiedName& tagName, Document*, HTMLFormElement*);
 
     virtual void parseAttribute(const QualifiedName&, const AtomicString&) OVERRIDE;
     virtual void requiredAttributeChanged();
     virtual void disabledAttributeChanged();
     virtual void attach();
     virtual InsertionNotificationRequest insertedInto(ContainerNode*) OVERRIDE;
     virtual void removedFrom(ContainerNode*) OVERRIDE;
     virtual void didMoveToNewDocument(Document* oldDocument) OVERRIDE;
@@ skipping 48 matching lines @@
     bool m_isValid : 1;
 
     bool m_wasChangedSinceLastFormControlChangeEvent : 1;
 
     bool m_hasAutofocused : 1;
 };
 
 } // namespace
 
 #endif