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

Source/core/html/HTMLOutputElement.cpp

Index: Source/core/html/HTMLOutputElement.cpp
diff --git a/Source/core/html/HTMLOutputElement.cpp b/Source/core/html/HTMLOutputElement.cpp
index d196825dfb7d0184dd9771869837f246b1091f60..4f2a9c4902a5ecf1f3615a9a229d7c79507539c9 100644
--- a/Source/core/html/HTMLOutputElement.cpp
+++ b/Source/core/html/HTMLOutputElement.cpp
@@ -47,9 +47,9 @@ inline HTMLOutputElement::HTMLOutputElement(const QualifiedName& tagName, Docume
     ScriptWrappable::init(this);
 }
 
-PassRefPtr<HTMLOutputElement> HTMLOutputElement::create(const QualifiedName& tagName, Document* document, HTMLFormElement* form)
+Result<HTMLOutputElement> HTMLOutputElement::create(const QualifiedName& tagName, Document* document, HTMLFormElement* form)
 {
-    return adoptRef(new HTMLOutputElement(tagName, document, form));
+    return adoptNode(new HTMLOutputElement(tagName, document, form));
 }
 
 const AtomicString& HTMLOutputElement::formControlType() const
@@ -142,4 +142,9 @@ void HTMLOutputElement::setTextContentInternal(const String& value)
     setTextContent(value, IGNORE_EXCEPTION);
 }
 
+void HTMLOutputElement::acceptHeapVisitor(Visitor* visitor) const
+{
+    HTMLFormControlElement::acceptHeapVisitor(visitor);
+}
+
 } // namespace