Use isSVG*Element() helpers more in SVG code (Part 1)

Source/core/svg/SVGFontFaceElement.cpp

 /*
  * Copyright (C) 2007 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2008 Apple Inc. 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.
  *
@@ skipping 257 matching lines @@
     return m_fontElement;
 }
 
 void SVGFontFaceElement::rebuildFontFace()
 {
     if (!inDocument()) {
         ASSERT(!m_fontElement);
         return;
     }
 
-    bool describesParentFont = parentNode()->hasTagName(SVGNames::fontTag);
+    bool describesParentFont = isSVGFontElement(*parentNode());
     RefPtrWillBeRawPtr<CSSValueList> list;
 
     if (describesParentFont) {
         m_fontElement = toSVGFontElement(parentNode());
 
         list = CSSValueList::createCommaSeparated();
         list->append(CSSFontFaceSrcValue::createLocal(fontFamily()));
     } else {
         m_fontElement = 0;
         // we currently ignore all but the last src element, alternatively we could concat them
-        for (Node* child = lastChild(); child && !list; child = child->previousSibling()) {
-            if (child->hasTagName(font_face_srcTag)) {
-                list = toSVGFontFaceSrcElement(child)->srcValue();
-                break;
-            }
-        }
+        if (SVGFontFaceSrcElement* element = Traversal<SVGFontFaceSrcElement>::lastChild(*this))
+            list = element->srcValue();
     }
 
     if (!list || !list->length())
         return;
 
     // Parse in-memory CSS rules
     m_fontFaceRule->mutableProperties().addParsedProperty(CSSProperty(CSSPropertySrc, list));
 
     if (describesParentFont) {
         // Traverse parsed CSS values and associate CSSFontFaceSrcValue elements with ourselves.
@@ skipping 44 matching lines @@
 
 void SVGFontFaceElement::childrenChanged(bool changedByParser, Node* beforeChange, Node* afterChange, int childCountDelta)
 {
     SVGElement::childrenChanged(changedByParser, beforeChange, afterChange, childCountDelta);
     rebuildFontFace();
 }
 
 } // namespace WebCore
 
 #endif // ENABLE(SVG_FONTS)