UA shadow root of <marquee> should not be exposed to user scripts

Source/core/dom/Element.cpp

Index: Source/core/dom/Element.cpp
diff --git a/Source/core/dom/Element.cpp b/Source/core/dom/Element.cpp
index 008fb9055e6258dde22c6474eb0809919eb8d8ec..ca628a32c111b71f5c604a14d3b6d16fa3d37752 100644
--- a/Source/core/dom/Element.cpp
+++ b/Source/core/dom/Element.cpp
@@ -1671,6 +1671,11 @@ PassRefPtrWillBeRawPtr<ShadowRoot> Element::createShadowRoot(ExceptionState& exc
     return PassRefPtrWillBeRawPtr<ShadowRoot>(ensureShadow().addShadowRoot(*this, ShadowRoot::AuthorShadowRoot));
 }
 
+PassRefPtrWillBeRawPtr<ShadowRoot> Element::createUserAgentShadowRoot(ExceptionState& exceptionState)
+{
+    return PassRefPtrWillBeRawPtr<ShadowRoot>(ensureUserAgentShadowRoot());
+}
+
 ShadowRoot* Element::shadowRoot() const
 {
     ElementShadow* elementShadow = shadow();