Make RenderObject::style() return a const object

Source/core/html/HTMLProgressElement.cpp

 /*
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
  *
  * 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
@@ skipping 40 matching lines @@
 {
 }
 
 PassRefPtrWillBeRawPtr<HTMLProgressElement> HTMLProgressElement::create(Document& document)
 {
     RefPtrWillBeRawPtr<HTMLProgressElement> progress = adoptRefWillBeNoop(new HTMLProgressElement(document));
     progress->ensureUserAgentShadowRoot();
     return progress.release();
 }
 
-RenderObject* HTMLProgressElement::createRenderer(RenderStyle* style)
+RenderObject* HTMLProgressElement::createRenderer(const RenderStyle* style)
 {
     if (!style->hasAppearance() || hasAuthorShadowRoot())
         return RenderObject::createObject(this, style);
 
     return new RenderProgress(this);
 }
 
 RenderProgress* HTMLProgressElement::renderProgress() const
 {
     if (renderer() && renderer()->isProgress())
@@ skipping 99 matching lines @@
     return !isDeterminate();
 }
 
 void HTMLProgressElement::trace(Visitor* visitor)
 {
     visitor->trace(m_value);
     LabelableElement::trace(visitor);
 }
 
 } // namespace