Chrome roll.

tools/dom/scripts/idlnode.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 os
 import sys
 
 
 class IDLNode(object):
@@ skipping 290 matching lines @@
         assert value is None
         func_value = None
         ctor_args = self._find_first(ext_attr, 'ExtAttrArgList')
         if ctor_args:
           func_value = IDLExtAttrFunctionValue(None, ctor_args)
         self.setdefault('Constructor', []).append(func_value)
         continue
 
       func_value = self._find_first(value, 'ExtAttrFunctionValue')
       if func_value:
-        # E.g. NamedConstructor=Audio(in [Optional] DOMString src)
+        # E.g. NamedConstructor=Audio(optional DOMString src)
         self[name] = IDLExtAttrFunctionValue(
             func_value,
             self._find_first(func_value, 'ExtAttrArgList'))
         continue
 
       self[name] = value
 
   def _all_subnodes(self):
     # Extended attributes may contain IDLNodes, e.g. IDLExtAttrFunctionValue
     return self.values()
@@ skipping 168 matching lines @@
   def __init__(self, ast, doc_js_interface_name):
     IDLMember.__init__(self, ast, doc_js_interface_name)
     self.value = self._find_first(ast, 'ConstExpr')
 
 
 class IDLArgument(IDLNode):
   """IDLNode specialization for operation arguments."""
   def __init__(self, ast):
     IDLNode.__init__(self, ast)
     self.type = self._convert_first(ast, 'Type', IDLType)
+    self.optional = self._has(ast, 'Optional')
     self._convert_ext_attrs(ast)
 
   def __repr__(self):
     return '<IDLArgument(type = %s, id = %s)>' % (self.type, self.id)
 
 
 class IDLImplementsStatement(IDLNode):
   """IDLNode specialization for 'X implements Y' declarations."""
   def __init__(self, ast):
     IDLNode.__init__(self, ast)
@@ skipping 20 matching lines @@
   """IDLDictNode specialization for one annotation."""
   def __init__(self, ast=None):
     IDLDictNode.__init__(self, ast)
     self.id = None
     if not ast:
       return
     for arg in self._find_all(ast, 'AnnotationArg'):
       name = self._find_first(arg, 'Id')
       value = self._find_first(arg, 'AnnotationArgValue')
       self[name] = value