Adding ASSERT for RuntimeEnabled feature XSLT

Source/core/xml/XSLImportRule.h

 /*
  * This file is part of the XSL implementation.
  *
  * Copyright (C) 2004, 2006, 2008 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.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  *
  */
 
 #ifndef XSLImportRule_h
 #define XSLImportRule_h
 
+#include "RuntimeEnabledFeatures.h"
 #include "core/fetch/ResourcePtr.h"
 #include "core/fetch/StyleSheetResourceClient.h"
 #include "core/xml/XSLStyleSheet.h"
 #include "wtf/PassOwnPtr.h"
 
 namespace WebCore {
 
 class XSLStyleSheetResource;
 
 class XSLImportRule : private StyleSheetResourceClient {
     WTF_MAKE_FAST_ALLOCATED;
 public:
     static PassOwnPtr<XSLImportRule> create(XSLStyleSheet* parentSheet, const String& href)
     {
+        ASSERT(RuntimeEnabledFeatures::xsltEnabled());
         return adoptPtr(new XSLImportRule(parentSheet, href));
     }
 
     virtual ~XSLImportRule();
 
     const String& href() const { return m_strHref; }
     XSLStyleSheet* styleSheet() const { return m_styleSheet.get(); }
 
     XSLStyleSheet* parentStyleSheet() const { return m_parentStyleSheet; }
     void setParentStyleSheet(XSLStyleSheet* styleSheet) { m_parentStyleSheet = styleSheet; }
 
     bool isLoading();
     void loadSheet();
 
 private:
     XSLImportRule(XSLStyleSheet* parentSheet, const String& href);
 
     virtual void setXSLStyleSheet(const String& href, const KURL& baseURL, const String& sheet);
 
     XSLStyleSheet* m_parentStyleSheet;
     String m_strHref;
     RefPtr<XSLStyleSheet> m_styleSheet;
     ResourcePtr<XSLStyleSheetResource> m_resource;
     bool m_loading;
 };
 
 } // namespace WebCore
 
 #endif // XSLImportRule_h