Add "Failed" custom element state

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Peter Kelly (pmk@post.com)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012, 2013 Apple Inc. All rights reserved.
  *           (C) 2007 Eric Seidel (eric@webkit.org)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 1941 matching lines @@
 }
 
 ShadowRoot* Element::attachShadow(const ScriptState* scriptState, const ShadowRootInit& shadowRootInitDict, ExceptionState& exceptionState)
 {
     DCHECK(RuntimeEnabledFeatures::shadowDOMV1Enabled());
 
     HostsUsingFeatures::countMainWorldOnly(scriptState, document(), HostsUsingFeatures::Feature::ElementAttachShadow);
 
     const AtomicString& tagName = localName();
     bool tagNameIsSupported = isV0CustomElement()
-        || isCustomElement()
+        || getCustomElementState() != CustomElementState::Uncustomized
         || tagName == HTMLNames::articleTag
         || tagName == HTMLNames::asideTag
         || tagName == HTMLNames::blockquoteTag
         || tagName == HTMLNames::bodyTag
         || tagName == HTMLNames::divTag
         || tagName == HTMLNames::footerTag
         || tagName == HTMLNames::h1Tag
         || tagName == HTMLNames::h2Tag
         || tagName == HTMLNames::h3Tag
         || tagName == HTMLNames::h4Tag
@@ skipping 1796 matching lines @@
 
 DEFINE_TRACE_WRAPPERS(Element)
 {
     if (hasRareData()) {
         visitor->traceWrappers(elementRareData());
     }
     ContainerNode::traceWrappers(visitor);
 }
 
 } // namespace blink