Pass implementation object to supplemental classes by reference

Source/core/svg/SVGZoomAndPan.cpp

 /*
  * Copyright (C) 2004, 2005, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007 Rob Buis <buis@kde.org>
  * Copyright (C) 2014 Samsung Electronics. 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 57 matching lines @@
 bool SVGZoomAndPan::parseZoomAndPan(const LChar*& start, const LChar* end)
 {
     return parseZoomAndPanInternal(start, end, m_zoomAndPan);
 }
 
 bool SVGZoomAndPan::parseZoomAndPan(const UChar*& start, const UChar* end)
 {
     return parseZoomAndPanInternal(start, end, m_zoomAndPan);
 }
 
-void SVGZoomAndPan::setZoomAndPan(SVGViewSpec*, unsigned short, ExceptionState& exceptionState)
+void SVGZoomAndPan::setZoomAndPan(SVGViewSpec&, unsigned short, ExceptionState& exceptionState)
 {
     // SVGViewSpec and all of its content is read-only.
     exceptionState.throwDOMException(NoModificationAllowedError, ExceptionMessages::readOnly());
 }
 
 }