Sync the DOM traversal interfaces with the spec

Source/core/dom/NodeFilter.idl

 /*
  * Copyright (C) 2006, 2007, 2008 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,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 
+// https://dom.spec.whatwg.org/#interface-nodefilter
+
+// FIXME: NodeFilter should be a callback interface. crbug.com/462946
 [
     DependentLifetime,
     WillBeGarbageCollected,
 ] interface NodeFilter {
-    // Constants returned by acceptNode
-    const short               FILTER_ACCEPT                  = 1;
-    const short               FILTER_REJECT                  = 2;
-    const short               FILTER_SKIP                    = 3;
+    // Constants for acceptNode()
+    // FIXME: acceptNode()'s return type and these constants should be unsigned short.
+    const short FILTER_ACCEPT = 1;
+    const short FILTER_REJECT = 2;
+    const short FILTER_SKIP = 3;
 
     // Constants for whatToShow
-    const unsigned long       SHOW_ALL                       = 0xFFFFFFFF;
-    const unsigned long       SHOW_ELEMENT                   = 0x00000001;
-    const unsigned long       SHOW_ATTRIBUTE                 = 0x00000002;
-    const unsigned long       SHOW_TEXT                      = 0x00000004;
-    const unsigned long       SHOW_CDATA_SECTION             = 0x00000008;
-    const unsigned long       SHOW_ENTITY_REFERENCE          = 0x00000010;
-    const unsigned long       SHOW_ENTITY                    = 0x00000020;
-    const unsigned long       SHOW_PROCESSING_INSTRUCTION    = 0x00000040;
-    const unsigned long       SHOW_COMMENT                   = 0x00000080;
-    const unsigned long       SHOW_DOCUMENT                  = 0x00000100;
-    const unsigned long       SHOW_DOCUMENT_TYPE             = 0x00000200;
-    const unsigned long       SHOW_DOCUMENT_FRAGMENT         = 0x00000400;
-    const unsigned long       SHOW_NOTATION                  = 0x00000800;
+    const unsigned long SHOW_ALL = 0xFFFFFFFF;
+    const unsigned long SHOW_ELEMENT = 0x1;
+    const unsigned long SHOW_ATTRIBUTE = 0x2; // historical
+    const unsigned long SHOW_TEXT = 0x4;
+    const unsigned long SHOW_CDATA_SECTION = 0x8; // historical
+    const unsigned long SHOW_ENTITY_REFERENCE = 0x10; // historical
+    const unsigned long SHOW_ENTITY = 0x20; // historical
+    const unsigned long SHOW_PROCESSING_INSTRUCTION = 0x40;
+    const unsigned long SHOW_COMMENT = 0x80;
+    const unsigned long SHOW_DOCUMENT = 0x100;
+    const unsigned long SHOW_DOCUMENT_TYPE = 0x200;
+    const unsigned long SHOW_DOCUMENT_FRAGMENT = 0x400;
+    const unsigned long SHOW_NOTATION = 0x800; // historical
 
-    [RaisesException] short acceptNode([Default=Undefined] optional Node n);
-
+    // FIXME: The node argument should not be optional.
+    [RaisesException] short acceptNode([Default=Undefined] optional Node node);
 };