SVG: Move/rename reference management to SVGElement

Source/core/svg/SVGDocumentExtensions.h

Index: Source/core/svg/SVGDocumentExtensions.h
diff --git a/Source/core/svg/SVGDocumentExtensions.h b/Source/core/svg/SVGDocumentExtensions.h
index 6ed1a6ebe8fabd1db12bf14b37b9586830c3caa0..5a7628dc4de5a30566236baaa77d0d69752531b7 100644
--- a/Source/core/svg/SVGDocumentExtensions.h
+++ b/Source/core/svg/SVGDocumentExtensions.h
@@ -41,8 +41,6 @@ class SVGResourcesCache;
 class SVGSVGElement;
 class Element;
 
-typedef WillBeHeapHashSet<RawPtrWillBeMember<SVGElement> > SVGElementSet;
-
 class SVGDocumentExtensions : public NoBaseWillBeGarbageCollectedFinalized<SVGDocumentExtensions> {
     WTF_MAKE_NONCOPYABLE(SVGDocumentExtensions); WTF_MAKE_FAST_ALLOCATED_WILL_BE_REMOVED;
 public:
@@ -68,12 +66,6 @@ public:
 
     SVGResourcesCache* resourcesCache() const { return m_resourcesCache.get(); }
 
-    SVGElementSet* setOfElementsReferencingTarget(SVGElement* referencedElement) const;
-    void addElementReferencingTarget(SVGElement* referencingElement, SVGElement* referencedElement);
-    void removeAllTargetReferencesForElement(SVGElement*);
-    void rebuildAllElementReferencesForTarget(SVGElement*);
-    void removeAllElementReferencesForTarget(SVGElement*);
-
     void addSVGRootWithRelativeLengthDescendents(SVGSVGElement*);
     void removeSVGRootWithRelativeLengthDescendents(SVGSVGElement*);
     bool isSVGRootWithRelativeLengthDescendents(SVGSVGElement*) const;