SVG objects with same idrefs conflict when under different shadow root

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

Index: third_party/WebKit/Source/core/svg/SVGElement.h
diff --git a/third_party/WebKit/Source/core/svg/SVGElement.h b/third_party/WebKit/Source/core/svg/SVGElement.h
index 9edb14d39d76144a48dbb5fb1d43180f6e2a02f9..5b6f69ceb879a3f6c3b4a3d376042c9fb4e8a863 100644
--- a/third_party/WebKit/Source/core/svg/SVGElement.h
+++ b/third_party/WebKit/Source/core/svg/SVGElement.h
@@ -58,6 +58,10 @@ class CORE_EXPORT SVGElement : public Element {
   int tabIndex() const override;
   bool supportsFocus() const override { return false; }
 
+  // The TreeScope this element should resolve id's against. This differs from
+  // the regular Node::treeScope() by taking <use> into account.
+  TreeScope& treeScopeForIdResolution() const;
+
   bool isOutermostSVGSVGElement() const;
 
   bool hasTagName(const SVGQualifiedName& name) const {