1 files changed, 10 insertions, 9 deletions
diff --git a/chromium/third_party/blink/renderer/core/html/custom/custom_element.cc b/chromium/third_party/blink/renderer/core/html/custom/custom_element.cc
index d21c582052c..1a031cecfab 100644
--- a/chromium/third_party/blink/renderer/core/html/custom/custom_element.cc
+++ b/chromium/third_party/blink/renderer/core/html/custom/custom_element.cc
@@ -56,8 +56,7 @@ Vector<AtomicString>& CustomElement::EmbedderCustomElementNames() {
 void CustomElement::AddEmbedderCustomElementName(const AtomicString& name) {
   DCHECK_EQ(name, name.LowerASCII());
   DCHECK(Document::IsValidName(name)) << name;
-  DCHECK_EQ(HTMLElementType::kHTMLUnknownElement, htmlElementTypeForTag(name))
-      << name;
+  DCHECK(!IsKnownBuiltinTagName(name)) << name;
   DCHECK(!IsValidName(name, false)) << name;
 
   if (EmbedderCustomElementNames().Contains(name))
@@ -69,8 +68,7 @@ void CustomElement::AddEmbedderCustomElementNameForTesting(
     const AtomicString& name,
     ExceptionState& exception_state) {
   if (name != name.LowerASCII() || !Document::IsValidName(name) ||
-      HTMLElementType::kHTMLUnknownElement != htmlElementTypeForTag(name) ||
-      IsValidName(name, false)) {
+      IsKnownBuiltinTagName(name) || IsValidName(name, false)) {
     exception_state.ThrowDOMException(DOMExceptionCode::kSyntaxError,
                                       "Name cannot be used");
     return;
@@ -105,14 +103,16 @@ bool CustomElement::ShouldCreateCustomElement(const QualifiedName& tag_name) {
 }
 
 bool CustomElement::ShouldCreateCustomizedBuiltinElement(
-    const AtomicString& local_name) {
-  return htmlElementTypeForTag(local_name) !=
+    const AtomicString& local_name,
+    const Document& document) {
+  return htmlElementTypeForTag(local_name, &document) !=
          HTMLElementType::kHTMLUnknownElement;
 }
 
 bool CustomElement::ShouldCreateCustomizedBuiltinElement(
-    const QualifiedName& tag_name) {
-  return ShouldCreateCustomizedBuiltinElement(tag_name.LocalName()) &&
+    const QualifiedName& tag_name,
+    const Document& document) {
+  return ShouldCreateCustomizedBuiltinElement(tag_name.LocalName(), document) &&
          tag_name.NamespaceURI() == html_names::xhtmlNamespaceURI;
 }
 
@@ -205,7 +205,8 @@ Element* CustomElement::CreateUncustomizedOrUndefinedElement(
 
 HTMLElement* CustomElement::CreateFailedElement(Document& document,
                                                 const QualifiedName& tag_name) {
-  DCHECK(ShouldCreateCustomElement(tag_name));
+  CHECK(ShouldCreateCustomElement(tag_name))
+      << "HTMLUnknownElement with built-in tag name: " << tag_name;
 
   // "create an element for a token":
   // https://html.spec.whatwg.org/C/#create-an-element-for-the-token