Add "Failed" custom element state

third_party/WebKit/Source/core/dom/custom/CustomElementDefinition.cpp

Index: third_party/WebKit/Source/core/dom/custom/CustomElementDefinition.cpp
diff --git a/third_party/WebKit/Source/core/dom/custom/CustomElementDefinition.cpp b/third_party/WebKit/Source/core/dom/custom/CustomElementDefinition.cpp
index e0567a9029abf1241defa983378311411da865fd..58cdf981056351cd6189c98c31e1554929b28748 100644
--- a/third_party/WebKit/Source/core/dom/custom/CustomElementDefinition.cpp
+++ b/third_party/WebKit/Source/core/dom/custom/CustomElementDefinition.cpp
@@ -120,8 +120,10 @@ void CustomElementDefinition::upgrade(Element* element)
     DCHECK_EQ(m_constructionStack.size(), depth); // It's a *stack*.
     m_constructionStack.removeLast();
 
-    if (!succeeded)
+    if (!succeeded) {
+        element->setCustomElementState(CustomElementState::Failed);
         return;
+    }
 
     CHECK(element->getCustomElementState() == CustomElementState::Custom);
 }