Use an SVGElementProxy in ReferenceClipPathOperation

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

Index: third_party/WebKit/Source/core/svg/SVGElementRareData.h
diff --git a/third_party/WebKit/Source/core/svg/SVGElementRareData.h b/third_party/WebKit/Source/core/svg/SVGElementRareData.h
index c2549c90b31f80b8e149dbeca7645b6afe247bc6..e8a8eddf32b7c8de67495c6a84a8f5ba2bfc7083 100644
--- a/third_party/WebKit/Source/core/svg/SVGElementRareData.h
+++ b/third_party/WebKit/Source/core/svg/SVGElementRareData.h
@@ -31,6 +31,7 @@ namespace blink {
 
 class CSSCursorImageValue;
 class SVGCursorElement;
+class SVGElementProxySet;
 
 class SVGElementRareData
     : public GarbageCollectedFinalized<SVGElementRareData> {
@@ -56,6 +57,8 @@ class SVGElementRareData
     return m_incomingReferences;
   }
 
+  SVGElementProxySet& ensureElementProxySet();
+
   HeapHashSet<WeakMember<SVGElement>>& elementInstances() {
     return m_elementInstances;
   }
@@ -125,6 +128,7 @@ class SVGElementRareData
   HeapHashSet<WeakMember<SVGElement>> m_elementInstances;
   WeakMember<SVGCursorElement> m_cursorElement;
   WeakMember<const CSSCursorImageValue> m_cursorImageValue;
+  Member<SVGElementProxySet> m_elementProxySet;
   Member<SVGElement> m_correspondingElement;
   bool m_instancesUpdatesBlocked : 1;
   bool m_useOverrideComputedStyle : 1;