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
index 9a7b95aaf0d4decd1d17a5be7d0736daf9bad57a..0031840020e44e33c42c85c3986d06144ea58d9b 100644
--- a/tests/lib_2/lib_2_dart2js.status
+++ b/tests/lib_2/lib_2_dart2js.status
@@ -11,6 +11,13 @@ async/catch_errors28_test: Fail # Timer interface not supported: Issue 7728.
 async/future_test: RuntimeError # Timer interface not supported; Issue 7728.
 async/future_constructor2_test: Fail # Timer interface not supported: Issue 7728.
 async/multiple_timer_test: RuntimeError,OK # Needs Timer to run.
+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
 
 [ $compiler == dart2js ]
 async/future_or_strong_test: RuntimeError