Remove TreatNullAs=NullString for Element.id and .className

Source/core/dom/Element.idl

 /*
  * Copyright (C) 2006, 2007, 2009 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 39 matching lines @@
     [MeasureAs=ElementGetAttributeNodeNS] Attr getAttributeNodeNS([TreatNullAs=NullString,Default=Undefined] optional DOMString namespaceURI,
                                                                   [Default=Undefined] optional DOMString localName); // Removed from DOM4.
     [RaisesException, CustomElementCallbacks] Attr setAttributeNodeNS([Default=Undefined, StrictTypeChecking] optional Attr newAttr);
     boolean hasAttribute(DOMString name);
     boolean hasAttributeNS([TreatNullAs=NullString,Default=Undefined] optional DOMString namespaceURI,
                            [Default=Undefined] optional DOMString localName);
 
     [PerWorldBindings] readonly attribute CSSStyleDeclaration style;
 
     // DOM4
-    // iht.com relies on id returning the empty string when no id is present.
-    // Other browsers do this as well. So we don't convert null to JS null.
-    [Reflect, TreatNullAs=NullString] attribute DOMString id;
+    [Reflect] attribute DOMString id;
     [TreatReturnedNullStringAs=Null, PerWorldBindings] readonly attribute DOMString namespaceURI;
     [TreatReturnedNullStringAs=Null, TreatNullAs=NullString, PerWorldBindings, RaisesException=Setter] attribute DOMString prefix;
     [TreatReturnedNullStringAs=Null, PerWorldBindings] readonly attribute DOMString localName;
 
     // Common extensions
 
     [PerWorldBindings] readonly attribute long offsetLeft;
     [PerWorldBindings] readonly attribute long offsetTop;
     [PerWorldBindings] readonly attribute long offsetWidth;
     [PerWorldBindings] readonly attribute long offsetHeight;
@@ skipping 15 matching lines @@
 
     void scrollIntoViewIfNeeded(optional boolean centerIfNeeded);
     void scrollByLines([Default=Undefined] optional long lines);
     void scrollByPages([Default=Undefined] optional long pages);
 
     // HTML 5
     NodeList getElementsByClassName([Default=Undefined] optional DOMString name);
     [TreatNullAs=NullString, CustomElementCallbacks, PerWorldBindings, ActivityLogging=SetterForIsolatedWorlds, RaisesException=Setter] attribute DOMString innerHTML;
     [TreatNullAs=NullString, CustomElementCallbacks, RaisesException=Setter] attribute DOMString outerHTML;
 
-    [Reflect=class, TreatNullAs=NullString, PerWorldBindings] attribute DOMString className;
+    [Reflect=class, PerWorldBindings] attribute DOMString className;
     [PerWorldBindings] readonly attribute DOMTokenList classList;
 
     [PerWorldBindings] readonly attribute DOMStringMap dataset;
 
     // NodeSelector - Selector API
     [RaisesException] Element querySelector(DOMString selectors);
     [RaisesException] NodeList querySelectorAll(DOMString selectors);
 
     // WebKit extension, pending specification.
     [RaisesException] boolean webkitMatchesSelector([Default=Undefined] optional DOMString selectors);
@@ skipping 39 matching lines @@
     [RuntimeEnabled=Touch] attribute EventHandler ontouchend;
     [RuntimeEnabled=Touch] attribute EventHandler ontouchmove;
     [RuntimeEnabled=Touch] attribute EventHandler ontouchstart;
     attribute EventHandler onwebkitfullscreenchange;
     attribute EventHandler onwebkitfullscreenerror;
     [PerWorldBindings, ActivityLogging=SetterForIsolatedWorlds] attribute EventHandler onwheel;
 };
 
 Element implements ParentNode;
 Element implements ChildNode;