IDL: initialize union member variables (to null/zero)

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 388 matching lines @@
         property_attributes_list.append('v8::ReadOnly')
     if property_attributes_list:
         property_attributes_list.insert(0, 'v8::DontDelete')
     return property_attributes_list
 
 
 def union_member_argument_context(idl_type, index):
     """Returns a context of union member for argument."""
     this_cpp_value = 'result%d' % index
     this_cpp_type = idl_type.cpp_type
+    this_cpp_type_initializer = idl_type.cpp_type_initializer
     cpp_return_value = this_cpp_value
 
     if not idl_type.cpp_type_has_null_value:
         this_cpp_type = v8_types.cpp_template_type('Nullable', this_cpp_type)
+        this_cpp_type_initializer = ''
         cpp_return_value = '%s.get()' % this_cpp_value
 
     if idl_type.is_string_type:
         null_check_value = '!%s.isNull()' % this_cpp_value
     else:
         null_check_value = this_cpp_value
 
     return {
         'cpp_type': this_cpp_type,
+        'cpp_type_initializer': this_cpp_type_initializer,
         'cpp_value': this_cpp_value,
         'null_check_value': null_check_value,
         'v8_set_return_value': idl_type.v8_set_return_value(
             cpp_value=cpp_return_value,
             release=idl_type.release),
     }
 
 
 def union_arguments(idl_type):
     return [union_member_argument_context(member_idl_type, index)
             for index, member_idl_type
             in enumerate(idl_type.member_types)]
 
 
 def argument_default_cpp_value(argument):
     if not argument.default_value:
         return None
     return argument.idl_type.literal_cpp_value(argument.default_value)
 
 IdlTypeBase.union_arguments = None
 IdlUnionType.union_arguments = property(union_arguments)
 IdlArgument.default_cpp_value = property(argument_default_cpp_value)