Use isSVG*Element() helpers more in SVG code (Part 3)

Source/core/rendering/svg/RenderSVGResourceFilter.cpp

 /*
  * 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 65 matching lines @@
     markClientForInvalidation(client, markForInvalidation ? BoundariesInvalidation : ParentOnlyInvalidation);
 }
 
 PassRefPtr<SVGFilterBuilder> RenderSVGResourceFilter::buildPrimitives(SVGFilter* filter)
 {
     SVGFilterElement* filterElement = toSVGFilterElement(element());
     FloatRect targetBoundingBox = filter->targetBoundingBox();
 
     // Add effects to the builder
     RefPtr<SVGFilterBuilder> builder = SVGFilterBuilder::create(SourceGraphic::create(filter), SourceAlpha::create(filter));
-    for (Element* child = ElementTraversal::firstWithin(*filterElement); child; child = ElementTraversal::nextSibling(*child)) {
-        if (!child->isSVGElement())
-            continue;
-
-        SVGElement* element = toSVGElement(child);
+    for (SVGElement* element = Traversal<SVGElement>::firstChild(*filterElement); element; element = Traversal<SVGElement>::nextSibling(*element)) {
         if (!element->isFilterEffect() || !element->renderer())
             continue;
 
         SVGFilterPrimitiveStandardAttributes* effectElement = static_cast<SVGFilterPrimitiveStandardAttributes*>(element);
         RefPtr<FilterEffect> effect = effectElement->build(builder.get(), filter);
         if (!effect) {
             builder->clearEffects();
             return nullptr;
         }
         builder->appendEffectToEffectReferences(effect, effectElement->renderer());
@@ skipping 292 matching lines @@
     markAllClientLayersForInvalidation();
 }
 
 FloatRect RenderSVGResourceFilter::drawingRegion(RenderObject* object) const
 {
     FilterData* filterData = m_filter.get(object);
     return filterData ? filterData->drawingRegion : FloatRect();
 }
 
 }