Support WebIDL's ExtendedAttributeIdentList in the Blink parser

Source/bindings/scripts/idl_validator.py

 # Copyright (C) 2013 Google Inc. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 # copyright notice, this list of conditions and the following disclaimer
@@ skipping 60 matching lines @@
                 'Unknown extended attribute [%s]' % name)
         valid_values = self.valid_extended_attributes[name]
         if values_string is None and None not in valid_values:
             raise IDLInvalidExtendedAttributeError(
                 'Missing required argument for extended attribute [%s]' % name)
         if '*' in valid_values:  # wildcard, any (non-empty) value ok
             return
         if values_string is None:
             values = set([None])
         else:
-            values = set(re.split('[|&]', values_string))
+            values = set(re.split('[|,]', values_string))
         invalid_values = values - valid_values
         if invalid_values:
             invalid_value = invalid_values.pop()
             raise IDLInvalidExtendedAttributeError(
                 'Invalid value "%s" found in extended attribute [%s=%s]' %
                 (invalid_value, name, values_string))
 
 
 def read_extended_attributes_file():
     def extended_attribute_name_values():
         with open(EXTENDED_ATTRIBUTES_FILENAME) as extended_attributes_file:
             for line in extended_attributes_file:
                 line = line.strip()
                 if not line or line.startswith('#'):
                     continue
                 name, _, values_string = map(str.strip, line.partition('='))
                 value_list = [value.strip() for value in values_string.split('|')]
                 yield name, value_list
 
     valid_extended_attributes = {}
     for name, value_list in extended_attribute_name_values():
         if not value_list:
             valid_extended_attributes[name] = set([None])
             continue
         valid_extended_attributes[name] = set([value if value else None
                                                for value in value_list])
     return valid_extended_attributes