Const-ify static s_resourceType members in RenderSVGResouce* classes

Source/core/rendering/svg/RenderSVGResourceFilter.h

 /*
  * Copyright (C) 2004, 2005, 2006, 2007 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005 Rob Buis <buis@kde.org>
  * Copyright (C) 2005 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2009 Dirk Schulze <krit@webkit.org>
  * 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
@@ skipping 58 matching lines @@
 
     FloatRect resourceBoundingBox(const RenderObject*);
 
     PassRefPtr<SVGFilterBuilder> buildPrimitives(SVGFilter*);
 
     SVGUnitTypes::SVGUnitType filterUnits() const { return toSVGFilterElement(element())->filterUnits()->currentValue()->enumValue(); }
     SVGUnitTypes::SVGUnitType primitiveUnits() const { return toSVGFilterElement(element())->primitiveUnits()->currentValue()->enumValue(); }
 
     void primitiveAttributeChanged(RenderObject*, const QualifiedName&);
 
+    static const RenderSVGResourceType s_resourceType = FilterResourceType;
     virtual RenderSVGResourceType resourceType() const override { return s_resourceType; }
-    static const RenderSVGResourceType s_resourceType;
 
     FloatRect drawingRegion(RenderObject*) const;
 private:
     typedef HashMap<RenderObject*, OwnPtr<FilterData> > FilterMap;
     FilterMap m_filter;
 };
 
 DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderSVGResourceFilter, isSVGResourceFilter());
 
 }
 
 #endif