Let unresolved custom element go through CustomElementCallbackQueue.

Source/core/dom/custom/CustomElementRegistrationContext.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 42 matching lines @@
 
     ~CustomElementRegistrationContext() { }
 
     // Definitions
     void registerElement(Document*, CustomElementConstructorBuilder*, const AtomicString& type, CustomElement::NameSet validNames, ExceptionState&);
 
     PassRefPtr<Element> createCustomTagElement(Document&, const QualifiedName&);
     static void setIsAttributeAndTypeExtension(Element*, const AtomicString& type);
     static void setTypeExtension(Element*, const AtomicString& type);
 
+    void resolve(Element*, const CustomElementDescriptor&);
+
 protected:
     CustomElementRegistrationContext() { }
 
     // Instance creation
     void didGiveTypeExtension(Element*, const AtomicString& type);
 
 private:
-    void resolve(Element*, const AtomicString& typeExtension);
-    void didResolveElement(CustomElementDefinition*, Element*);
-    void didCreateUnresolvedElement(const CustomElementDescriptor&, Element*);
+    void scheduleResolution(Element*, const AtomicString& typeExtension);
 
     CustomElementRegistry m_registry;
 
     // Element creation
     CustomElementUpgradeCandidateMap m_candidates;
 };
 
 }
 
 #endif // CustomElementRegistrationContext_h