SVG objects with same idrefs conflict when under different shadow root

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

Index: third_party/WebKit/Source/core/dom/TreeScope.cpp
diff --git a/third_party/WebKit/Source/core/dom/TreeScope.cpp b/third_party/WebKit/Source/core/dom/TreeScope.cpp
index aad09a602220767557321f7afd69b671e26a09ea..f75cd05267bb5bee08670743a73120d86faac4f5 100644
--- a/third_party/WebKit/Source/core/dom/TreeScope.cpp
+++ b/third_party/WebKit/Source/core/dom/TreeScope.cpp
@@ -52,6 +52,7 @@
 #include "core/layout/api/LayoutViewItem.h"
 #include "core/page/FocusController.h"
 #include "core/page/Page.h"
+#include "core/svg/SVGTreeScopeResources.h"
 #include "wtf/Vector.h"
 
 namespace blink {
@@ -338,6 +339,16 @@ HeapVector<Member<Element>> TreeScope::elementsFromPoint(int x, int y) const {
   return elementsFromHitTestResult(result);
 }
 
+const SVGTreeScopeResources* TreeScope::svgExtensions() {
+  return m_svgTreeScopedResources;
+}
+
+SVGTreeScopeResources& TreeScope::accessSVGTreeScopedResources() {
+  if (!m_svgTreeScopedResources)
+    m_svgTreeScopedResources = new SVGTreeScopeResources(this);
+  return *m_svgTreeScopedResources;
+}
+
 DOMSelection* TreeScope::getSelection() const {
   if (!rootNode().document().frame())
     return nullptr;
@@ -566,6 +577,7 @@ DEFINE_TRACE(TreeScope) {
   visitor->trace(m_imageMapsByName);
   visitor->trace(m_scopedStyleResolver);
   visitor->trace(m_radioButtonGroupScope);
+  visitor->trace(m_svgTreeScopedResources);
 }
 
 }  // namespace blink