Make RenderObject::style() return a const object

Source/core/html/HTMLWBRElement.h

 /*
  * Copyright (C) 2014 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 26 matching lines @@
 
 // <wbr> is an HTMLElement in script, but we use a separate interface here
 // so HTMLElement's createRenderer doesn't need to know about it.
 class HTMLWBRElement final : public HTMLElement {
 public:
     DECLARE_NODE_FACTORY(HTMLWBRElement);
 
 private:
     explicit HTMLWBRElement(Document&);
 
-    virtual RenderObject* createRenderer(RenderStyle*) override;
+    virtual RenderObject* createRenderer(const RenderStyle*) override;
 };
 
 } // namespace
 
 #endif