Deprecate unused feature DOMImplementationCreateCSSStyleSheet

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 19 matching lines @@
 
     [RaisesException] DocumentType createDocumentType(DOMString qualifiedName,
                                                       DOMString publicId,
                                                       DOMString systemId);
     [RaisesException] Document createDocument([TreatNullAs=NullString] DOMString namespaceURI,
                                               [TreatNullAs=NullString] DOMString qualifiedName,
                                               [Default=Undefined] optional DocumentType doctype);
 
     // DOMImplementationCSS interface from DOM Level 2 CSS
 
-    [MeasureAs=DOMImplementationCreateCSSStyleSheet]
+    [DeprecateAs=DOMImplementationCreateCSSStyleSheet]

[Inactive, 2014/01/24 14:08:48]

I believe you also need to add a deprecation message to UseCounter.cpp. Likely,
some layout tests will need rebasing after that as well due to the deprecation
warning.

[philipj_slow, 2014/01/24 14:45:53]

Indeed, without such a message you will hit an assert. Since there is no
replacement, I can only suggest the somewhat unhelpful deprecation message
"'DOMImplementation.createCSSStyleSheet()' is deprecated."

     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);
 };