Remove the compile time flag for DATALIST Element.

Source/core/html/HTMLOptionElement.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, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Google 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
@@ skipping 32 matching lines @@
     void setText(const String&, ExceptionCode&);
 
     int index() const;
 
     String value() const;
     void setValue(const String&);
 
     bool selected();
     void setSelected(bool);
 
-#if ENABLE(DATALIST_ELEMENT)
     HTMLDataListElement* ownerDataListElement() const;
-#endif
     HTMLSelectElement* ownerSelectElement() const;
 
     String label() const;
     void setLabel(const String&);
 
     bool ownElementDisabled() const { return m_disabled; }
 
     virtual bool isDisabledFormControl() const OVERRIDE;
 
     String textIndentedToRespectGroupLabel() const;
@@ skipping 46 matching lines @@
 inline const HTMLOptionElement* toHTMLOptionElement(const Node* node)
 {
     return static_cast<const HTMLOptionElement*>(node);
 }
 
 #endif
 
 } // namespace
 
 #endif