Do not special case null for URLUtils attributes

Source/core/html/HTMLAnchorElement.idl

 /*
  * Copyright (C) 2006, 2007, 2009, 2010 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 14 matching lines @@
     [Reflect, URL] attribute DOMString href;
     [Reflect] attribute DOMString hreflang;
     [Reflect] attribute DOMString name;
     [Reflect] attribute DOMString ping;
     [Reflect] attribute DOMString rel;
     [Reflect] attribute DOMString rev;
     [Reflect] attribute DOMString shape;
     [Reflect] attribute DOMString target;
     [Reflect] attribute DOMString type;
 
-    [TreatNullAs=NullString] attribute DOMString hash;
-    [TreatNullAs=NullString] attribute DOMString host;
-    [TreatNullAs=NullString] attribute DOMString hostname;
-    [TreatNullAs=NullString] attribute DOMString pathname;
-    [TreatNullAs=NullString] attribute DOMString port;
-    [TreatNullAs=NullString] attribute DOMString protocol;
-    [TreatNullAs=NullString] attribute DOMString search;
+    attribute DOMString hash;
+    attribute DOMString host;
+    attribute DOMString hostname;
+    attribute DOMString pathname;
+    attribute DOMString port;
+    attribute DOMString protocol;
+    attribute DOMString search;
 
-    [TreatNullAs=NullString] readonly attribute DOMString origin;
+    readonly attribute DOMString origin;
 
     readonly attribute DOMString text;
 
     [NotEnumerable] DOMString toString();
 };