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

Source/core/svg/SVGFontFaceSrcElement.cpp

Index: Source/core/svg/SVGFontFaceSrcElement.cpp
diff --git a/Source/core/svg/SVGFontFaceSrcElement.cpp b/Source/core/svg/SVGFontFaceSrcElement.cpp
index 5bb34db4b9fa017ab7f7c76bf9ff0a0c63bd9dec..f1cd5a5e7d0d2b9bfe7576ed150ab4349911e420 100644
--- a/Source/core/svg/SVGFontFaceSrcElement.cpp
+++ b/Source/core/svg/SVGFontFaceSrcElement.cpp
@@ -25,6 +25,7 @@
 #include "SVGNames.h"
 #include "core/css/CSSFontFaceSrcValue.h"
 #include "core/css/CSSValueList.h"
+#include "core/dom/ElementTraversal.h"
 #include "core/svg/SVGFontFaceElement.h"
 #include "core/svg/SVGFontFaceNameElement.h"
 #include "core/svg/SVGFontFaceUriElement.h"
@@ -47,12 +48,12 @@ PassRefPtr<SVGFontFaceSrcElement> SVGFontFaceSrcElement::create(Document& docume
 PassRefPtrWillBeRawPtr<CSSValueList> SVGFontFaceSrcElement::srcValue() const
 {
     RefPtrWillBeRawPtr<CSSValueList> list = CSSValueList::createCommaSeparated();
-    for (Node* child = firstChild(); child; child = child->nextSibling()) {
+    for (SVGElement* element = Traversal<SVGElement>::firstChild(*this); element; element = Traversal<SVGElement>::nextSibling(*element)) {
         RefPtrWillBeRawPtr<CSSFontFaceSrcValue> srcValue;
-        if (child->hasTagName(font_face_uriTag))
-            srcValue = toSVGFontFaceUriElement(child)->srcValue();
-        else if (child->hasTagName(font_face_nameTag))
-            srcValue = toSVGFontFaceNameElement(child)->srcValue();
+        if (isSVGFontFaceUriElement(*element))
+            srcValue = toSVGFontFaceUriElement(*element).srcValue();
+        else if (isSVGFontFaceNameElement(*element))
+            srcValue = toSVGFontFaceNameElement(*element).srcValue();
 
         if (srcValue && srcValue->resource().length())
             list->append(srcValue);
@@ -63,8 +64,8 @@ PassRefPtrWillBeRawPtr<CSSValueList> SVGFontFaceSrcElement::srcValue() const
 void SVGFontFaceSrcElement::childrenChanged(bool changedByParser, Node* beforeChange, Node* afterChange, int childCountDelta)
 {
     SVGElement::childrenChanged(changedByParser, beforeChange, afterChange, childCountDelta);
-    if (parentNode() && parentNode()->hasTagName(font_faceTag))
-        toSVGFontFaceElement(parentNode())->rebuildFontFace();
+    if (isSVGFontFaceElement(parentNode()))
+        toSVGFontFaceElement(*parentNode()).rebuildFontFace();
 }
 
 }