IDL: Support argument default values

Source/bindings/scripts/v8_methods.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 283 matching lines @@
 
     return '%s(%s)' % (macro, ', '.join(macro_args))
 
 
 def v8_value_to_local_cpp_value(argument, index):
     extended_attributes = argument.extended_attributes
     idl_type = argument.idl_type
     name = argument.name
     if argument.is_variadic:
         return v8_value_to_local_cpp_variadic_value(argument, index)
-    # FIXME: This special way of handling string arguments with null defaults
-    # can go away once we fully support default values.
-    if (argument.is_optional and idl_type.name in ('String', 'ByteString') and
-        argument.default_value and argument.default_value.is_null):
-        v8_value = 'argumentOrNull(info, %s)' % index
-    else:
-        v8_value = 'info[%s]' % index
-    return idl_type.v8_value_to_local_cpp_value(extended_attributes, v8_value,
+    return idl_type.v8_value_to_local_cpp_value(extended_attributes, 'info[%s]' % index,
                                                 name, index=index, declare_variable=False)
 
 
 ################################################################################
 # Auxiliary functions
 ################################################################################
 
 # [NotEnumerable]
 def property_attributes(method):
     extended_attributes = method.extended_attributes
     property_attributes_list = []
     if 'NotEnumerable' in extended_attributes:
         property_attributes_list.append('v8::DontEnum')
     if 'ReadOnly' in extended_attributes:
         property_attributes_list.append('v8::ReadOnly')
     if property_attributes_list:
         property_attributes_list.insert(0, 'v8::DontDelete')
     return property_attributes_list
 
 
 def union_arguments(idl_type):
     """Return list of ['result0Enabled', 'result0', 'result1Enabled', ...] for union types, for use in setting return value"""
     return [arg
             for i in range(len(idl_type.member_types))
             for arg in ['result%sEnabled' % i, 'result%s' % i]]
 
 IdlType.union_arguments = property(lambda self: None)
 IdlUnionType.union_arguments = property(union_arguments)