Use more const, more RefPtrs while iterating the SVG shadow tree.

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.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 16 matching lines @@
 #include "core/svg/SVGGeometryElement.h"
 #include "core/svg/SVGGraphicsElement.h"
 #include "core/svg/SVGURIReference.h"
 #include "platform/heap/Handle.h"
 
 namespace blink {
 
 typedef EventSender<SVGUseElement> SVGUseEventSender;
 
 class SVGUseElement final : public SVGGraphicsElement,
-                            public SVGURIReference,
-                            public DocumentResourceClient {
+    public SVGURIReference,
+    public DocumentResourceClient {
+
     DEFINE_WRAPPERTYPEINFO();
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(SVGUseElement);
 public:
     static PassRefPtrWillBeRawPtr<SVGUseElement> create(Document&);
     ~SVGUseElement() override;
 
     void invalidateShadowTree();
 
     // Return the element that should be used for clipping,
     // or null if a valid clip element is not directly referenced.
@@ skipping 41 matching lines @@
     bool buildShadowTree(SVGElement* target, SVGElement* targetInstance, bool foundUse);
     void clearShadowTree();
     bool hasCycleUseReferencing(SVGUseElement*, ContainerNode* targetInstance, SVGElement*& newTarget);
     bool expandUseElementsInShadowTree(SVGElement*);
     void expandSymbolElementsInShadowTree(SVGElement*);
 
     void transferUseAttributesToReplacedElement(SVGElement* from, SVGElement* to) const;
 
     void invalidateDependentShadowTrees();
 
-    bool resourceIsStillLoading();
+    bool resourceIsStillLoading() const;
     Document* externalDocument() const;
-    bool instanceTreeIsLoading(SVGElement*);
+    bool instanceTreeIsLoading(const SVGElement*);
     void notifyFinished(Resource*) override;
     TreeScope* referencedScope() const;
     void setDocumentResource(ResourcePtr<DocumentResource>);
 
     RefPtrWillBeMember<SVGAnimatedLength> m_x;
     RefPtrWillBeMember<SVGAnimatedLength> m_y;
     RefPtrWillBeMember<SVGAnimatedLength> m_width;
     RefPtrWillBeMember<SVGAnimatedLength> m_height;
 
     bool m_haveFiredLoadEvent;
     bool m_needsShadowTreeRecreation;
     RefPtrWillBeMember<SVGElement> m_targetElementInstance;
     ResourcePtr<DocumentResource> m_resource;
 };
 
 } // namespace blink
 
 #endif // SVGUseElement_h