Remove embedder custom elements.

sky/engine/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 39 matching lines @@
 class CustomElementRegistrationContext final : public RefCounted<CustomElementRegistrationContext> {
 public:
     static PassRefPtr<CustomElementRegistrationContext> create()
     {
         return adoptRef(new CustomElementRegistrationContext());
     }
 
     ~CustomElementRegistrationContext() { }
 
     // Definitions
-    void registerElement(Document*, CustomElementConstructorBuilder*, const AtomicString& type, CustomElement::NameSet validNames, ExceptionState&);
+    void registerElement(Document*, CustomElementConstructorBuilder*, const AtomicString& type, ExceptionState&);
 
     PassRefPtr<Element> createCustomTagElement(Document&, const QualifiedName&);
 
     void resolve(Element*, const CustomElementDescriptor&);
 
 protected:
     CustomElementRegistrationContext();
 
 private:
     void resolveOrScheduleResolution(Element*);
 
     CustomElementRegistry m_registry;
 };
 
 }
 
 #endif  // SKY_ENGINE_CORE_DOM_CUSTOM_CUSTOMELEMENTREGISTRATIONCONTEXT_H_