Bindings generation emits (more) correct null checking

Source/bindings/dart/scripts/dart_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 184 matching lines @@
         # Only expose as optional if no default value.
         'is_optional': argument.is_optional and not (this_has_default or argument.default_value),
         'is_strict_type_checking': 'StrictTypeChecking' in extended_attributes,
         'is_variadic_wrapper_type': is_variadic_wrapper_type,
         'vector_type': 'WillBeHeapVector' if use_heap_vector_type else 'Vector',
         'is_wrapper_type': idl_type.is_wrapper_type,
         'name': argument.name,
         'dart_set_return_value_for_main_world': dart_set_return_value(interface.name, method, this_cpp_value, for_main_world=True),
         'dart_set_return_value': dart_set_return_value(interface.name, method, this_cpp_value),
         'arg_index': arg_index,
-        'dart_value_to_local_cpp_value': dart_value_to_local_cpp_value(argument, arg_index, auto_scope),
+        'dart_value_to_local_cpp_value': dart_value_to_local_cpp_value(interface, argument, arg_index, auto_scope),
     }
     return argument_data
 
 
 ################################################################################
 # Value handling
 ################################################################################
 
 def cpp_value(interface, method, number_of_arguments):
     def cpp_argument(argument):
@@ skipping 63 matching lines @@
 
     auto_scope = not 'DartNoAutoScope' in extended_attributes
     script_wrappable = 'impl' if inherits_interface(interface_name, 'Node') else ''
     return idl_type.dart_set_return_value(cpp_value, extended_attributes,
                                           script_wrappable=script_wrappable,
                                           release=release,
                                           for_main_world=for_main_world,
                                           auto_scope=auto_scope)
 
 
-def dart_value_to_local_cpp_value(argument, index, auto_scope=True):
+def dart_value_to_local_cpp_value(interface, argument, index, auto_scope=True):
     extended_attributes = argument.extended_attributes
+    interface_extended_attributes = interface.extended_attributes
     idl_type = argument.idl_type
     name = argument.name
     # TODO(terry): Variadic arguments are not handled but treated as one argument.
     #    if argument.is_variadic:
     #        vector_type = 'WillBeHeapVector' if idl_type.is_will_be_garbage_collected else 'Vector'
     #        return 'V8TRYCATCH_VOID({vector_type}<{cpp_type}>, {name}, toNativeArguments<{cpp_type}>(info, {index}))'.format(
     #                cpp_type=idl_type.cpp_type, name=name, index=index, vector_type=vector_type)
 
     # FIXME: V8 has some special logic around the addEventListener and
     # removeEventListener methods that should be added in somewhere.
     # There is also some logic in systemnative.py to force a null check
     # for the useCapture argument of those same methods that we may need to
     # pull over.
     null_check = (argument.is_optional and \
                   (idl_type.is_callback_interface or idl_type == 'Dictionary')) or \
                  (argument.default_value and argument.default_value.is_null)
 
     return idl_type.dart_value_to_local_cpp_value(
-        argument.extended_attributes, name, null_check,
+        interface_extended_attributes, extended_attributes, name, null_check,
         index=index, auto_scope=auto_scope)
 
 
 ################################################################################
 # 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)