fix #603, support mock objects

test/browser/language_tests.js

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 (function() {
   'use strict';
 
   let dart_sdk = dart_library.import('dart_sdk');
   dart_sdk._isolate_helper.startRootIsolate(function() {}, []);
   let async_helper = dart_library.import('async_helper').async_helper;
@@ skipping 241 matching lines @@
       'mixin_mixin_test': skip_fail,
       'mixin_regress_13688_test': skip_fail,
       'mixin_type_parameter1_test': skip_fail,
       'mixin_type_parameter2_test': skip_fail,
       'mixin_type_parameter3_test': skip_fail,
       'modulo_test': fail,
       'named_parameter_clash_test': skip_fail,
       'nan_identical_test': skip_fail,
       'nested_switch_label_test': skip_fail,
       'no_such_method_empty_selector_test': fail,
-      'no_such_method_subtype_test': fail,
       'number_identifier_test_05_multi': skip_fail,
       'number_identity2_test': skip_fail,
       'numbers_test': skip_fail,
       'optimized_hoisting_checked_mode_assert_test': skip_fail,
       'redirecting_factory_reflection_test': skip_fail,
       'regress_13462_0_test': skip_fail,
       'regress_13462_1_test': skip_fail,
       'regress_14105_test': skip_fail,
       'regress_16640_test': skip_fail,
       'regress_18535_test': skip_fail,
@@ skipping 2632 matching lines @@
 
     for (let action of unittest_tests) {
       try {
         action();
       } catch (e) {
         console.error("Caught error tying to setup test:", e);
       }
     }
   });
 })();