Pass more const RenderObject& in the vicinity of paint-servers

Source/core/rendering/svg/RenderSVGResourceSolidColor.h

 /*
  * Copyright (C) Research In Motion Limited 2010. 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.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 12 matching lines @@
 #include "core/rendering/svg/RenderSVGResource.h"
 #include "platform/graphics/Color.h"
 
 namespace blink {
 
 class RenderSVGResourceSolidColor final : public RenderSVGResource {
 public:
     RenderSVGResourceSolidColor();
     virtual ~RenderSVGResourceSolidColor();
 
-    virtual SVGPaintServer preparePaintServer(RenderObject*) override;
+    virtual SVGPaintServer preparePaintServer(const RenderObject&) override;
 
     virtual RenderSVGResourceType resourceType() const override { return s_resourceType; }
     static const RenderSVGResourceType s_resourceType;
 
     const Color& color() const { return m_color; }
     void setColor(const Color& color) { m_color = color; }
 
 private:
     Color m_color;
 };
 
 }
 
 #endif