Make several DOMImplementation API arguments mandatory

Source/core/dom/DOMImplementation.idl

 /*
  * Copyright (C) 2006, 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Samuel Weinig <sam.weinig@gmail.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 11 matching lines @@
     GenerateIsReachable=document
 ] interface DOMImplementation {
 
     // DOM Level 1
 
      boolean hasFeature([Default=Undefined] optional DOMString feature,
                                       [TreatNullAs=NullString,Default=Undefined] optional DOMString version);
 
     // DOM Level 2
 
-     [RaisesException] DocumentType createDocumentType([TreatNullAs=NullString, TreatUndefinedAs=NullString,Default=Undefined] optional DOMString qualifiedName,
-                                                   [TreatNullAs=NullString, TreatUndefinedAs=NullString,Default=Undefined] optional DOMString publicId,
-                                                   [TreatNullAs=NullString, TreatUndefinedAs=NullString,Default=Undefined] optional DOMString systemId);
-     [RaisesException] Document createDocument([TreatNullAs=NullString,Default=Undefined] optional DOMString namespaceURI,
-                                           [TreatNullAs=NullString,Default=Undefined] optional DOMString qualifiedName,
-                                           [TreatNullAs=NullString,Default=Undefined] optional DocumentType doctype);
+     [RaisesException] DocumentType createDocumentType([TreatNullAs=NullString] DOMString qualifiedName,
+                                                       [TreatNullAs=NullString] DOMString publicId,
+                                                       [TreatNullAs=NullString] DOMString systemId);
+     [RaisesException] Document createDocument([TreatNullAs=NullString] DOMString namespaceURI,
+                                               [TreatNullAs=NullString] DOMString qualifiedName,
+                                               [Default=Undefined] optional DocumentType doctype);

[arv (Not doing code reviews), 2013/08/16 13:33:27]

Why is [Default=Undefined] needed?

[do-not-use, 2013/08/16 13:47:03]

It did not compile otherwise because the implementation looks like:
PassRefPtr<Document> createDocument(const String& namespaceURI, const String&
qualifiedName, DocumentType*, ExceptionState&);

There is no such overload:
PassRefPtr<Document> createDocument(const String& namespaceURI, const String&
qualifiedName, ExceptionState&);

[arv (Not doing code reviews), 2013/08/16 13:59:09]

Why not [Default=Null]?

 
     // DOMImplementationCSS interface from DOM Level 2 CSS
 
      CSSStyleSheet createCSSStyleSheet([Default=Undefined] optional DOMString title,
                                        [Default=Undefined] optional DOMString media);
 
     // HTMLDOMImplementation interface from DOM Level 2 HTML
 
     HTMLDocument createHTMLDocument([Default=NullString] optional DOMString title);
 };