Implemented Document.contentType

Source/core/dom/Document.idl

 /*
  * Copyright (C) 2006, 2007, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2006, 2007 Samuel Weinig <sam@webkit.org>
  *
  * 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 69 matching lines @@
 
     // DOM Level 2 Style (DocumentStyle interface)
 
     readonly attribute StyleSheetList styleSheets;
 
     // DOM Level 2 Style (DocumentCSS interface)
 
      CSSStyleDeclaration getOverrideStyle([Default=Undefined] optional Element element,
                                                         [Default=Undefined] optional DOMString pseudoElement);
 
+    // DOM 4
+    readonly attribute DOMString contentType;
+
     // Common extensions
     [CustomElementCallbacks]
     boolean            execCommand([Default=Undefined] optional DOMString command,
                                    [Default=Undefined] optional boolean userInterface,
                                    [TreatNullAs=NullString, TreatUndefinedAs=NullString,Default=Undefined] optional DOMString value);
 
     boolean            queryCommandEnabled([Default=Undefined] optional DOMString command);
     boolean            queryCommandIndeterm([Default=Undefined] optional DOMString command);
     boolean            queryCommandState([Default=Undefined] optional DOMString command);
     boolean            queryCommandSupported([Default=Undefined] optional DOMString command);
@@ skipping 108 matching lines @@
     // document in the console. It's possible http://crbug.com/43394 will resolve this.
     [MeasureAs=PrefixedPageVisibility, ImplementedAs=visibilityState] readonly attribute DOMString webkitVisibilityState;
     [MeasureAs=PrefixedPageVisibility, ImplementedAs=hidden] readonly attribute boolean webkitHidden;
 
     readonly attribute HTMLScriptElement currentScript;
 };
 
 Document implements GlobalEventHandlers;
 Document implements ParentNode;