Use new Traversal<> API more in the code base

Source/core/rendering/svg/RenderSVGResourceClipper.cpp

 /*
  * Copyright (C) 2004, 2005, 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Rob Buis <buis@kde.org>
  * Copyright (C) Research In Motion Limited 2009-2010. All rights reserved.
  * Copyright (C) 2011 Dirk Schulze <krit@webkit.org>
  *
  * 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 73 matching lines @@
 }
 
 bool RenderSVGResourceClipper::tryPathOnlyClipping(GraphicsContext* context,
     const AffineTransform& animatedLocalTransform, const FloatRect& objectBoundingBox) {
     // If the current clip-path gets clipped itself, we have to fallback to masking.
     if (!style()->svgStyle().clipperResource().isEmpty())
         return false;
     WindRule clipRule = RULE_NONZERO;
     Path clipPath = Path();
 
-    for (Element* childElement = ElementTraversal::firstChild(*element()); childElement; childElement = ElementTraversal::nextSibling(*childElement)) {
+    for (SVGElement* childElement = Traversal<SVGElement>::firstChild(*element()); childElement; childElement = Traversal<SVGElement>::nextSibling(*childElement)) {
         RenderObject* renderer = childElement->renderer();
         if (!renderer)
             continue;
         // Only shapes or paths are supported for direct clipping. We need to fallback to masking for texts.
         if (renderer->isSVGText())
             return false;
-        if (!childElement->isSVGElement() || !toSVGElement(childElement)->isSVGGraphicsElement())
+        if (!childElement->isSVGGraphicsElement())
             continue;
         SVGGraphicsElement* styled = toSVGGraphicsElement(childElement);
         RenderStyle* style = renderer->style();
         if (!style || style->display() == NONE || style->visibility() != VISIBLE)
              continue;
         const SVGRenderStyle& svgStyle = style->svgStyle();
         // Current shape in clip-path gets clipped too. Fallback to masking.
         if (!svgStyle.clipperResource().isEmpty())
             return false;
 
@@ skipping 261 matching lines @@
         AffineTransform transform;
         transform.translate(objectBoundingBox.x(), objectBoundingBox.y());
         transform.scaleNonUniform(objectBoundingBox.width(), objectBoundingBox.height());
         return transform.mapRect(m_clipBoundaries);
     }
 
     return m_clipBoundaries;
 }
 
 }