Migrated test block 171 to Dart 2.0.

tests/lib_2/lib_2_dart2js.status

Index: tests/lib_2/lib_2_dart2js.status
diff --git a/tests/lib_2/lib_2_dart2js.status b/tests/lib_2/lib_2_dart2js.status
new file mode 100644
index 0000000000000000000000000000000000000000..adbcfd1b964c9dab570db286d26bd4b7782545b0
--- /dev/null
+++ b/tests/lib_2/lib_2_dart2js.status
@@ -0,0 +1,12 @@
+# Copyright (c) 2017, 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.
+
+[ $compiler == dart2js && $runtime == jsshell ]
+async/slow_consumer2_test: RuntimeError # Timer interface not supported; Issue 7728.
+async/slow_consumer3_test: RuntimeError # Timer interface not supported; Issue 7728.
+async/slow_consumer_test: RuntimeError # Timer interface not supported; Issue 7728.
+async/run_zoned7_test: RuntimeError # Timer interface not supported: Issue 7728.
+async/run_zoned8_test: Fail # Timer interface not supported: Issue 7728.
+async/schedule_microtask_test: Fail  # Preamble file does not correctly implement scheduleImmediate.
+async/schedule_microtask3_test: RuntimeError