Make RenderObject::style() return a const object

Source/core/html/shadow/ProgressShadowElement.cpp

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 45 matching lines @@
     return progressRenderer && !progressRenderer->style()->hasAppearance() && HTMLDivElement::rendererIsNeeded(style);
 }
 
 inline ProgressInnerElement::ProgressInnerElement(Document& document)
     : ProgressShadowElement(document)
 {
 }
 
 DEFINE_NODE_FACTORY(ProgressInnerElement)
 
-RenderObject* ProgressInnerElement::createRenderer(RenderStyle*)
+RenderObject* ProgressInnerElement::createRenderer(const RenderStyle*)
 {
     return new RenderProgress(this);
 }
 
 bool ProgressInnerElement::rendererIsNeeded(const RenderStyle& style)
 {
     if (progressElement()->hasAuthorShadowRoot())
         return HTMLDivElement::rendererIsNeeded(style);
 
     RenderObject* progressRenderer = progressElement()->renderer();
@@ skipping 13 matching lines @@
 }
 
 void ProgressValueElement::setWidthPercentage(double width)
 {
     setInlineStyleProperty(CSSPropertyWidth, width, CSSPrimitiveValue::CSS_PERCENTAGE);
 }
 
 DEFINE_NODE_FACTORY(ProgressValueElement)
 
 }