Make RenderObject::style() return a const object

Source/core/svg/SVGSVGElement.cpp

 /*
  * Copyright (C) 2004, 2005, 2006 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2010 Rob Buis <buis@kde.org>
  * Copyright (C) 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2014 Google, Inc.
  *
  * 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 499 matching lines @@
 {
     // FIXME: We should respect display: none on the documentElement svg element
     // but many things in FrameView and SVGImage depend on the RenderSVGRoot when
     // they should instead depend on the RenderView.
     // https://bugs.webkit.org/show_bug.cgi?id=103493
     if (document().documentElement() == this)
         return true;
     return Element::rendererIsNeeded(style);
 }
 
-RenderObject* SVGSVGElement::createRenderer(RenderStyle*)
+RenderObject* SVGSVGElement::createRenderer(const RenderStyle*)
 {
     if (isOutermostSVGSVGElement())
         return new RenderSVGRoot(this);
 
     return new RenderSVGViewportContainer(this);
 }
 
 Node::InsertionNotificationRequest SVGSVGElement::insertedInto(ContainerNode* rootParent)
 {
     if (rootParent->inDocument()) {
@@ skipping 240 matching lines @@
     visitor->trace(m_width);
     visitor->trace(m_height);
     visitor->trace(m_translation);
     visitor->trace(m_timeContainer);
     visitor->trace(m_viewSpec);
     SVGGraphicsElement::trace(visitor);
     SVGFitToViewBox::trace(visitor);
 }
 
 } // namespace blink