Make RenderObject::style() return a const object

Source/core/layout/LayoutThemeChromiumSkia.cpp

 /*
  * Copyright (C) 2007 Apple Inc.
  * Copyright (C) 2007 Alp Toker <alp@atoker.com>
  * Copyright (C) 2008 Collabora Ltd.
  * Copyright (C) 2008, 2009 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 114 matching lines @@
         return 0;
 
     return caretBlinkIntervalInternal();
 }
 
 void LayoutThemeChromiumSkia::systemFont(CSSValueID systemFontID, FontStyle& fontStyle, FontWeight& fontWeight, float& fontSize, AtomicString& fontFamily) const
 {
     LayoutThemeChromiumFontProvider::systemFont(systemFontID, fontStyle, fontWeight, fontSize, fontFamily);
 }
 
-int LayoutThemeChromiumSkia::minimumMenuListSize(RenderStyle* style) const
+int LayoutThemeChromiumSkia::minimumMenuListSize(const RenderStyle* style) const
 {
     return 0;
 }
 
 // These are the default dimensions of radio buttons and checkboxes.
 static const int widgetStandardWidth = 13;
 static const int widgetStandardHeight = 13;
 
 // Return a rectangle that has the same center point as |original|, but with a
 // size capped at |width| by |height|.
@@ skipping 340 matching lines @@
 }
 
 LayoutThemeChromiumSkia::DirectionFlippingScope::~DirectionFlippingScope()
 {
     if (!m_needsFlipping)
         return;
     m_paintInfo.context->restore();
 }
 
 } // namespace blink