Support Dart optional arguments which are not dispatched, but instead use default values.

client/dom/scripts/fremontcutbuilder.py

 #!/usr/bin/python
 # Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 import database
 import databasebuilder
 import idlparser
 import os.path
 import logging.config
@@ skipping 123 matching lines @@
         'DOMObject': 'object',
         'DOMSelection': 'Selection',
         'DOMWindow': 'Window',
         'Exception': 'DOMException',     # NotificationCenter.createNotification
         'SharedWorkerContext': 'SharedWorkerGlobalScope',
         'WorkerContext': 'WorkerGlobalScope',
       })
 
   optional_argument_whitelist = [
       ('CSSStyleDeclaration', 'setProperty', 'priority'),
-      # TODO(sra): Issue 1812 ('IDBDatabase', 'transaction', 'mode'),
+      ('IDBDatabase', 'transaction', 'mode'),
       ]
 
   for dir_name in webkit_dirs:
     dir_path = os.path.join(current_dir, '..', '..', '..', '..',
                 'third_party', 'WebKit', 'Source', 'WebCore', dir_name)
     builder.import_idl_directory(dir_path, webkit_options)
 
   webkit_supplemental_options = databasebuilder.DatabaseBuilderOptions(
     idl_syntax=idlparser.FREMONTCUT_SYNTAX,
     source='WebKit',
@@ skipping 22 matching lines @@
 
   builder.fix_displacements('WebKit')
 
   # Cleanup:
   builder.normalize_annotations(['WebKit', 'Dart'])
 
   db.Save()
 
 if __name__ == '__main__':
   sys.exit(main())