Use isSVG*Element() helpers more in SVG code (Part 2)

Source/core/svg/SVGHKernElement.cpp

Index: Source/core/svg/SVGHKernElement.cpp
diff --git a/Source/core/svg/SVGHKernElement.cpp b/Source/core/svg/SVGHKernElement.cpp
index cfd9229fdb8c49049d9fd983d1ab24c1c7acaa96..29042cd4f1cadd094aef6e0c2a815c25c275f7ac 100644
--- a/Source/core/svg/SVGHKernElement.cpp
+++ b/Source/core/svg/SVGHKernElement.cpp
@@ -41,8 +41,8 @@ PassRefPtr<SVGHKernElement> SVGHKernElement::create(Document& document)
 Node::InsertionNotificationRequest SVGHKernElement::insertedInto(ContainerNode* rootParent)
 {
     ContainerNode* fontNode = parentNode();
-    if (fontNode && fontNode->hasTagName(SVGNames::fontTag))
-        toSVGFontElement(fontNode)->invalidateGlyphCache();
+    if (isSVGFontElement(fontNode))
+        toSVGFontElement(*fontNode).invalidateGlyphCache();
 
     return SVGElement::insertedInto(rootParent);
 }
@@ -50,8 +50,8 @@ Node::InsertionNotificationRequest SVGHKernElement::insertedInto(ContainerNode*
 void SVGHKernElement::removedFrom(ContainerNode* rootParent)
 {
     ContainerNode* fontNode = parentNode();
-    if (fontNode && fontNode->hasTagName(SVGNames::fontTag))
-        toSVGFontElement(fontNode)->invalidateGlyphCache();
+    if (isSVGFontElement(fontNode))
+        toSVGFontElement(*fontNode).invalidateGlyphCache();
 
     SVGElement::removedFrom(rootParent);
 }