Chrome roll.

tools/dom/scripts/htmldartgenerator.py

 #!/usr/bin/python
 # Copyright (c) 2012, 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.
 
 """This module provides shared functionality for the system to generate
 dart:html APIs from the IDL database."""
 
 import emitter
 from generator import AnalyzeOperation, ConstantOutputOrder, \
@@ skipping 264 matching lines @@
           '    throw new ArgumentError("Incorrect number or type of arguments");'
           '\n');
     else:
       signature = signatures[0]
       argument_count = len(signature)
       for argument_position, argument in list(enumerate(signature))[::-1]:
         if is_optional(0, argument):
           check = '?%s' % parameter_names[argument_position]
           # argument_count instead of argument_position + 1 is used here to cover one
           # complicated case with the effectively optional argument in the middle.
-          # Consider foo(x, [Optional] y, [Optional=DefaultIsNullString] z)
+          # Consider foo(x, optional y, [Default=NullString] optional z)
           # (as of now it's modelled after HTMLMediaElement.webkitAddKey).
           # y is optional in WebCore, while z is not.
           # In this case, if y was actually passed, we'd like to emit foo(x, y, z) invocation,
           # not foo(x, y).
           GenerateCall(0, argument_count, [check])
           argument_count = argument_position
       GenerateCall(0, argument_count, [])
 
   def _GenerateDispatcherBody(self,
       operations,
@@ skipping 338 matching lines @@
         walk(interface.parents)
       else:
         walk(interface.parents[1:])
     return result
 
   def _DartType(self, type_name):
     return self._type_registry.DartType(type_name)
 
   def _IsPrivate(self, name):
     return name.startswith('_')