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

Source/core/svg/SVGUseElement.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007 Rob Buis <buis@kde.org>
  * Copyright (C) Research In Motion Limited 2009-2010. All rights reserved.
  * Copyright (C) 2011 Torch Mobile (Beijing) Co. Ltd. All rights reserved.
  * Copyright (C) 2012 University of Szeged
  * Copyright (C) 2012 Renata Hodovan <reni@webkit.org>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 225 matching lines @@
 
     ASSERT_NOT_REACHED();
 }
 
 #ifdef DUMP_INSTANCE_TREE
 static void dumpInstanceTree(unsigned int& depth, String& text, SVGElementInstance* targetInstance)
 {
     SVGElement* element = targetInstance->correspondingElement();
     ASSERT(element);
 
-    if (element->hasTagName(SVGNames::useTag)) {
-        if (toSVGUseElement(element)->resourceIsStillLoading())
-            return;
-    }
+    if (isSVGUseElement(*element) && toSVGUseElement(*element).resourceIsStillLoading())
+        return;
 
     SVGElement* shadowTreeElement = targetInstance->shadowTreeElement();
     ASSERT(shadowTreeElement);
 
     SVGUseElement* directUseElement = targetInstance->directUseElement();
     String directUseElementName = directUseElement ? directUseElement->nodeName() : "null";
 
     String elementId = element->getIdAttribute();
     String elementNodeName = element->nodeName();
     String shadowTreeElementNodeName = shadowTreeElement->nodeName();
@@ skipping 290 matching lines @@
     return 0;
 }
 
 void SVGUseElement::buildInstanceTree(SVGElement* target, SVGElementInstance* targetInstance, bool& foundProblem, bool foundUse)
 {
     ASSERT(target);
     ASSERT(targetInstance);
 
     // Spec: If the referenced object is itself a 'use', or if there are 'use' subelements within the referenced
     // object, the instance tree will contain recursive expansion of the indirect references to form a complete tree.
-    bool targetHasUseTag = target->hasTagName(SVGNames::useTag);
+    bool targetIsUseElement = isSVGUseElement(*target);
     SVGElement* newTarget = 0;
-    if (targetHasUseTag) {
+    if (targetIsUseElement) {
         foundProblem = hasCycleUseReferencing(toSVGUseElement(target), targetInstance, newTarget);
         if (foundProblem)
             return;
 
         // We only need to track first degree <use> dependencies. Indirect references are handled
         // as the invalidation bubbles up the dependency chain.
         if (!foundUse) {
             document().accessSVGExtensions().addElementReferencingTarget(this, target);
             foundUse = true;
         }
@@ skipping 22 matching lines @@
         RefPtr<SVGElementInstance> instance = SVGElementInstance::create(this, 0, element);
         SVGElementInstance* instancePtr = instance.get();
         targetInstance->appendChild(instance.release());
 
         // Enter recursion, appending new instance tree nodes to the "instance" object.
         buildInstanceTree(element, instancePtr, foundProblem, foundUse);
         if (foundProblem)
             return;
     }
 
-    if (!targetHasUseTag || !newTarget)
+    if (!targetIsUseElement || !newTarget)
         return;
 
     RefPtr<SVGElementInstance> newInstance = SVGElementInstance::create(this, toSVGUseElement(target), newTarget);
     SVGElementInstance* newInstancePtr = newInstance.get();
     targetInstance->appendChild(newInstance.release());
     buildInstanceTree(newTarget, newInstancePtr, foundProblem, foundUse);
 }
 
 bool SVGUseElement::hasCycleUseReferencing(SVGUseElement* use, SVGElementInstance* targetInstance, SVGElement*& newTarget)
 {
@@ skipping 53 matching lines @@
     // Though if there are disallowed elements in the subtree, we have to remove them.
     // For instance: <use> on <g> containing <foreignObject> (indirect case).
     if (subtreeContainsDisallowedElement(newChild.get()))
         removeDisallowedElementsFromSubtree(*newChild);
 
     userAgentShadowRoot()->appendChild(newChild.release());
 }
 
 void SVGUseElement::expandUseElementsInShadowTree(Node* element)
 {
+    ASSERT(element);
     // Why expand the <use> elements in the shadow tree here, and not just
     // do this directly in buildShadowTree, if we encounter a <use> element?
     //
     // Short answer: Because we may miss to expand some elements. Ie. if a <symbol>
     // contains <use> tags, we'd miss them. So once we're done with settin' up the
     // actual shadow tree (after the special case modification for svg/symbol) we have
     // to walk it completely and expand all <use> elements.
-    if (element->hasTagName(SVGNames::useTag)) {
+    if (isSVGUseElement(*element)) {
         SVGUseElement* use = toSVGUseElement(element);
         ASSERT(!use->resourceIsStillLoading());
 
         ASSERT(referencedDocument());
         Element* targetElement = SVGURIReference::targetElementFromIRIString(use->hrefString(), *referencedDocument());
         SVGElement* target = 0;
         if (targetElement && targetElement->isSVGElement())
             target = toSVGElement(targetElement);
 
         // Don't ASSERT(target) here, it may be "pending", too.
@@ skipping 277 matching lines @@
 
     if (m_resource)
         m_resource->removeClient(this);
 
     m_resource = resource;
     if (m_resource)
         m_resource->addClient(this);
 }
 
 }