Use IDL argument default values in Document.idl

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 54 matching lines @@
 
     [RaisesException] Event createEvent(DOMString eventType);
 
     // DOM Level 2 Traversal and Range (DocumentRange interface)
 
     Range createRange();
 
     // DOM Level 2 Traversal and Range (DocumentTraversal interface)
 
     [RaisesException] NodeIterator createNodeIterator(Node root,
-                                                      optional unsigned long whatToShow,
-                                                      optional NodeFilter filter);
+                                                      optional unsigned long whatToShow = 0xFFFFFFFF,
+                                                      optional NodeFilter? filter = null);
     [RaisesException] TreeWalker createTreeWalker(Node root,
-                                                  optional unsigned long whatToShow,
-                                                  optional NodeFilter filter);
+                                                  optional unsigned long whatToShow = 0xFFFFFFFF,
+                                                  optional NodeFilter? filter = null);
 
     // DOM Level 2 Abstract Views (DocumentView interface)
 
     [ImplementedAs=executingWindow] readonly attribute Window defaultView;
 
     // DOM Level 2 Style (DocumentStyle interface)
 
     readonly attribute StyleSheetList styleSheets;
 
     // DOM Level 2 Style (DocumentCSS interface)
@@ skipping 127 matching lines @@
     // TODO(davidben): This is a property so attaching a deprecation warning results in false positives when outputting
     // 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;