Fix build break in samples extension.

tests/standalone/standalone.status

 # Copyright (c) 2013, 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.
 
 # WARNING:
 # Tests using the multitest feature where failure is expected should *also* be
 # listed in tests/lib/analyzer/analyze_tests.status without the "standalone"
 # prefix.
 
 package/invalid_uri_test: Fail, OK # CompileTimeErrors intentionally
 
 [ $runtime == vm && $system == windows ]
 io/file_system_watcher_test: Pass, Timeout # Issue 13228
+io/platform_test.dart: Pass, Fail # Issue 14399
 
 [ $runtime == vm ]
 package/package_isolate_test: Fail # http://dartbug.com/7520.
 
 
 [ $runtime == vm && $checked ]
 # These tests have type errors on purpose.
 io/process_invalid_arguments_test: Fail, OK
 io/directory_invalid_arguments_test: Fail, OK
 io/file_invalid_arguments_test: Fail, OK
@@ skipping 154 matching lines @@
 io/test_extension_fail_test: Fail
 io/dart_std_io_pipe_test: Fail
 io/file_read_special_device_test: Fail
 
 [ $compiler == none && $runtime == dartium && $unchecked ]
 assert_test: Fail # Issue 13719: Please triage this failure.
 
 [ $compiler == none && $runtime == dartium ]
 javascript_int_overflow_literal_test/01: Fail # Issue 13719: Please triage this failure.
 javascript_int_overflow_test: Fail # Issue 13719: Please triage this failure.