Make RenderObject::style() return a const object

Source/core/rendering/InlineIterator.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2003, 2004, 2006, 2007, 2008, 2009, 2010 Apple Inc. All right reserved.
  * Copyright (C) 2010 Google Inc. 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 115 matching lines @@
         return dir == RTL ? RightToLeftEmbedding : LeftToRightEmbedding;
     return dir == RTL ? RightToLeftOverride : LeftToRightOverride;
 }
 
 template <class Observer>
 static inline void notifyObserverEnteredObject(Observer* observer, RenderObject* object)
 {
     if (!observer || !object || !object->isRenderInline())
         return;
 
-    RenderStyle* style = object->style();
+    const RenderStyle* style = object->style();
     EUnicodeBidi unicodeBidi = style->unicodeBidi();
     if (unicodeBidi == UBNormal) {
         // http://dev.w3.org/csswg/css3-writing-modes/#unicode-bidi
         // "The element does not open an additional level of embedding with respect to the bidirectional algorithm."
         // Thus we ignore any possible dir= attribute on the span.
         return;
     }
     if (isIsolated(unicodeBidi)) {
         // Make sure that explicit embeddings are committed before we enter the isolated content.
         observer->commitExplicitEmbedding(observer->runs());
@@ skipping 589 matching lines @@
         m_sor = m_eor;
     }
 
     m_direction = WTF::Unicode::OtherNeutral;
     m_status.eor = WTF::Unicode::OtherNeutral;
 }
 
 }
 
 #endif // InlineIterator_h