Implement Custom Elements 'extends' option.

Source/bindings/v8/CustomElementConstructorBuilder.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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 49 matching lines @@
 class CustomElementConstructorBuilder {
     WTF_MAKE_NONCOPYABLE(CustomElementConstructorBuilder);
 public:
     CustomElementConstructorBuilder(ScriptState*, const Dictionary* options);
 
     // The builder accumulates state and may run script at specific
     // points. These methods must be called in order. When one fails
     // (returns false), the calls must stop.
 
     bool isFeatureAllowed() const;
-    bool validateOptions(const AtomicString& type, ExceptionState&);
-    bool findTagName(const AtomicString& customElementType, QualifiedName& tagName);
+    bool validateOptions(const AtomicString& type, QualifiedName& tagName, ExceptionState&);
     PassRefPtr<CustomElementLifecycleCallbacks> createCallbacks();
     bool createConstructor(Document*, CustomElementDefinition*, ExceptionState&);
     bool didRegisterDefinition(CustomElementDefinition*) const;
 
     // This method collects a return value for the bindings. It is
     // safe to call this method even if the builder failed; it will
     // return an empty value.
     ScriptValue bindingsReturnValue() const;
 
 private:
-    static WrapperTypeInfo* findWrapperType(v8::Handle<v8::Value> chain);
     bool hasValidPrototypeChainFor(WrapperTypeInfo*) const;
     bool prototypeIsValid(const AtomicString& type, ExceptionState&) const;
     v8::Handle<v8::Function> retrieveCallback(v8::Isolate*, const char* name);
 
     v8::Handle<v8::Context> m_context;
     const Dictionary* m_options;
     v8::Handle<v8::Object> m_prototype;
     WrapperTypeInfo* m_wrapperType;
-    AtomicString m_namespaceURI;
     v8::Handle<v8::Function> m_constructor;
     RefPtr<V8CustomElementLifecycleCallbacks> m_callbacks;
 };
 
 }
 
 #endif // CustomElementConstructorBuilder_h