Change the type of a SVG <use> element's shadow tree from "user agent" to "closed"

third_party/WebKit/Source/core/svg/SVGUseElement.h

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Nikolas Zimmermann
  * <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007 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.
  *
@@ skipping 71 matching lines @@
   LayoutObject* createLayoutObject(const ComputedStyle&) override;
 
   void scheduleShadowTreeRecreation();
   void cancelShadowTreeRecreation();
   bool haveLoadedRequiredResources() override {
     return !isStructurallyExternal() || m_haveFiredLoadEvent;
   }
 
   bool selfHasRelativeLengths() const override;
 
+  ShadowRoot& useShadowRoot() const {
+    CHECK(closedShadowRoot());
+    return *closedShadowRoot();
+  }
+
   // Instance tree handling
   Element* resolveTargetElement();
   void buildShadowAndInstanceTree(SVGElement& target);
   void clearInstanceRoot();
   Element* createInstanceTree(SVGElement& targetRoot) const;
   void clearResourceReference();
   bool hasCycleUseReferencing(const SVGUseElement&,
                               const ContainerNode& targetInstance,
                               SVGElement*& newTarget) const;
   bool expandUseElementsInShadowTree();
@@ skipping 19 matching lines @@
   bool m_haveFiredLoadEvent;
   bool m_needsShadowTreeRecreation;
   Member<SVGElement> m_targetElementInstance;
   Member<IdTargetObserver> m_targetIdObserver;
   Member<DocumentResource> m_resource;
 };
 
 }  // namespace blink
 
 #endif  // SVGUseElement_h