IDL: Use Nullable for union type return value

Source/bindings/scripts/v8_types.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 193 matching lines @@
     """
 
     if (idl_type.is_numeric_type):
         return ' = 0'
     if idl_type.base_type == 'boolean':
         return ' = false'
     return ''
 
 
 def cpp_type_union(idl_type, extended_attributes=None, raw_type=False):
-    return (member_type.cpp_type for member_type in idl_type.member_types)
+    # FIXME: Need to revisit the design of union support.
+    # http://crbug.com/240176
+    return None
 
 
 def cpp_type_initializer_union(idl_type):
     return (member_type.cpp_type_initializer for member_type in idl_type.member_types)
 
 
 # Allow access as idl_type.cpp_type if no arguments
 IdlTypeBase.cpp_type = property(cpp_type)
 IdlTypeBase.cpp_type_initializer = property(cpp_type_initializer)
 IdlTypeBase.cpp_type_args = cpp_type
@@ skipping 486 matching lines @@
 
     format_string = V8_SET_RETURN_VALUE[this_v8_conversion_type]
     # FIXME: oilpan: Remove .release() once we remove all RefPtrs from generated code.
     if release:
         cpp_value = '%s.release()' % cpp_value
     statement = format_string.format(cpp_value=cpp_value, script_wrappable=script_wrappable)
     return statement
 
 
 def v8_set_return_value_union(idl_type, cpp_value, extended_attributes=None, script_wrappable='', release=False, for_main_world=False):
-    """
-    release: can be either False (False for all member types) or
-             a sequence (list or tuple) of booleans (if specified individually).
-    """
+    # FIXME: Need to revisit the design of union support.
+    # http://crbug.com/240176
+    return None
 
-    return [
-        member_type.v8_set_return_value(cpp_value + str(i),
-                                        extended_attributes,
-                                        script_wrappable,
-                                        release and release[i],
-                                        for_main_world)
-            for i, member_type in
-            enumerate(idl_type.member_types)]
 
 IdlTypeBase.v8_set_return_value = v8_set_return_value
 IdlUnionType.v8_set_return_value = v8_set_return_value_union
 
 IdlType.release = property(lambda self: self.is_interface_type)
 IdlUnionType.release = property(
     lambda self: [member_type.is_interface_type
                   for member_type in self.member_types])
 IdlArrayOrSequenceType.release = False
 
@@ skipping 69 matching lines @@
 
 
 def is_explicit_nullable(idl_type):
     # Nullable type that isn't implicit nullable (see above.) For such types,
     # we use Nullable<T> or similar explicit ways to represent a null value.
     return idl_type.is_nullable and not idl_type.is_implicit_nullable
 
 IdlTypeBase.is_implicit_nullable = property(is_implicit_nullable)
 IdlUnionType.is_implicit_nullable = False
 IdlTypeBase.is_explicit_nullable = property(is_explicit_nullable)