Use IdTargetObserver in SVGSMILElement

third_party/WebKit/Source/core/svg/SVGURIReference.cpp

 /*
  * Copyright (C) 2004, 2005, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006 Rob Buis <buis@kde.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.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 100 matching lines @@
   AtomicString id = fragmentIdentifierFromIRIString(urlString, treeScope);
   if (id.isEmpty())
     return nullptr;
   if (fragmentIdentifier)
     *fragmentIdentifier = id;
   return treeScope.getElementById(id);
 }
 
 Element* SVGURIReference::observeTarget(Member<IdTargetObserver>& observer,
                                         SVGElement& contextElement) {
+  return observeTarget(observer, contextElement, hrefString());
+}
+
+Element* SVGURIReference::observeTarget(Member<IdTargetObserver>& observer,
+                                        SVGElement& contextElement,
+                                        const String& hrefString) {
   TreeScope& treeScope = contextElement.treeScope();
-  AtomicString id = fragmentIdentifierFromIRIString(hrefString(), treeScope);
+  AtomicString id = fragmentIdentifierFromIRIString(hrefString, treeScope);
   return observeTarget(observer, treeScope, id,
                        WTF::bind(&SVGElement::buildPendingResource,
                                  wrapWeakPersistent(&contextElement)));
 }
 
 Element* SVGURIReference::observeTarget(Member<IdTargetObserver>& observer,
                                         TreeScope& treeScope,
                                         const AtomicString& id,
                                         std::unique_ptr<WTF::Closure> closure) {
   DCHECK(!observer);
   if (id.isEmpty())
     return nullptr;
   observer = new SVGElementReferenceObserver(treeScope, id, std::move(closure));
   return treeScope.getElementById(id);
 }
 
 void SVGURIReference::unobserveTarget(Member<IdTargetObserver>& observer) {
   if (!observer)
     return;
   observer->unregister();
   observer = nullptr;
 }
 
 }  // namespace blink