SVG object with same idrefs get conflicted even they are under different shadow root

third_party/WebKit/Source/core/dom/TreeScope.h

Index: third_party/WebKit/Source/core/dom/TreeScope.h
diff --git a/third_party/WebKit/Source/core/dom/TreeScope.h b/third_party/WebKit/Source/core/dom/TreeScope.h
index ce83da53b39f5a1119775f440d9b9b5b91e99cb6..4c07c982237a65e364aa4ba6e3419907745c378e 100644
--- a/third_party/WebKit/Source/core/dom/TreeScope.h
+++ b/third_party/WebKit/Source/core/dom/TreeScope.h
@@ -31,6 +31,7 @@
 #include "core/dom/DocumentOrderedMap.h"
 #include "core/html/forms/RadioButtonGroupScope.h"
 #include "core/layout/HitTestRequest.h"
+#include "core/svg/SVGTreeScopeResources.h"
 #include "platform/heap/Handle.h"
 #include "wtf/text/AtomicString.h"
 
@@ -115,6 +116,9 @@ public:
     ScopedStyleResolver& ensureScopedStyleResolver();
     void clearScopedStyleResolver();
 
+    const SVGTreeScopeResources* svgExtensions();
+    SVGTreeScopeResources& accessSVGTreeScopedResources();
+
 protected:
     TreeScope(ContainerNode&, Document&);
     TreeScope(Document&);
@@ -139,6 +143,9 @@ private:
     mutable Member<DOMSelection> m_selection;
 
     RadioButtonGroupScope m_radioButtonGroupScope;
+
+    Member<SVGTreeScopeResources> m_svgTreeScopedResources;
+
 };
 
 inline bool TreeScope::hasElementWithId(const AtomicString& id) const