Fix flaky stream_controller_async_test.

tests/lib/lib.status

 # Copyright (c) 2012, 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.
 
 [ $csp ]
 mirrors/delegate_test: RuntimeError # Issue 13864
 
 [ $compiler == dart2js ]
 async/schedule_microtask3_test: RuntimeError # _enqueueImmediate runs after Timer. http://dartbug.com/9002
 async/schedule_microtask4_test: Pass, RuntimeError # no global exception handler in isolates. http://dartbug.com/9012
 async/schedule_microtask6_test: RuntimeError # global error handling is not supported. http://dartbug.com/5958
-async/stream_controller_async_test: Pass, Fail # Issue 13608
 
 math/double_pow_test: RuntimeError
 math/low_test: RuntimeError
 math/random_test: RuntimeError
 
 mirrors/basic_types_in_dart_core_test: RuntimeError # Issue 14025
 mirrors/closures_test/none: RuntimeError # Issue 6490
 mirrors/closure_mirror_find_in_context_test: Fail # Issue 6490
 mirrors/constructor_kinds_test: RuntimeError # Issue 13799
 mirrors/equality_test/02: RuntimeError # Issue 12333
@@ skipping 136 matching lines @@
 typed_data/typed_data_hierarchy_int64_test: RuntimeError # Issue 10275
 
 [ $runtime == opera ]
 async/multiple_timer_test: Pass, Fail
 
 [ $runtime == opera && $system == windows]
 # TODO(efortuna): Investigate.
 async/timer_test: Fail, Pass
 
 [ $runtime == vm ]
-async/timer_not_available_test: Fail, OK 
+async/timer_not_available_test: Fail, OK
 mirrors/native_class_test: Fail, OK # This test is meant to run in a browser.
 
 [ $compiler == none  ]
 async/schedule_microtask3_test: Fail # _enqueueImmediate runs after Timer. http://dartbug.com/9001.
 mirrors/hierarchy_test: Fail # TODO(ahe): This test is slightly broken. http://dartbug.com/12464
 mirrors/mixin_application_test/01: Fail, OK # TODO(ahe): Slight broken test to ensure test coverage on dart2js.
 mirrors/intercepted_object_test: Fail, OK # TODO(ahe): Slight broken test to ensure test coverage on dart2js.
 mirrors/typedef_test/01: Fail, OK # Incorrect dart2js behavior.
 mirrors/closures_test/01: Fail, OK # Incorrect dart2js behavior.
 
@@ skipping 22 matching lines @@
 async/timer_test: Fail, Pass # See Issue 10982
 
 [ $arch == simmips || $arch == mips ]
 convert/chunked_conversion_utf88_test: Pass, Slow # Issue 12025.
 convert/streamed_conversion_json_utf8_decode_test: Pass, Slow
 
 [ $arch == simarm ]
 convert/chunked_conversion_utf88_test: Pass, Slow # Issue 12644.
 convert/utf85_test: Pass, Slow # Issue 12644.
 
-[ $compiler == none && ($runtime == vm || $runtime == dartium || $runtime == drt) ]
-async/stream_controller_async_test: Pass, Fail # Issue 13608
-
 [ $compiler == dartanalyzer ]
 mirrors/typedef_test/none: Fail # Issue 13093
 mirrors/generics_test/none: Fail # Issue 13432
 mirrors/generic_bounded_test/none: Fail # Issue 13432
 mirrors/generic_bounded_by_type_parameter_test/none: Fail # Issue 13432
 mirrors/generic_mixin_test/none: Fail # Issue 13432
 mirrors/invoke_named_test/none: Fail # http://dartbug.com/13612
 mirrors/generic_f_bounded_mixin_application_test: Fail # Issue 14116
 mirrors/generic_interface_test/none: Fail # Inexpressible in multitest
 
 # test issue 14016
 mirrors/typevariable_mirror_metadata_test: fail
 
 [ $compiler == dart2analyzer ]
 mirrors/typedef_test/none: Fail # Issue 13093
 mirrors/generics_test/none: Fail # Issue 13432
 mirrors/generic_bounded_test/none: Fail # Issue 13432
 mirrors/generic_bounded_by_type_parameter_test/none: Fail # Issue 13432
 mirrors/generic_mixin_test/none: Fail # Issue 13432
 mirrors/invoke_named_test/none: Fail # http://dartbug.com/13612
 mirrors/generic_f_bounded_mixin_application_test: Fail # Issue 14116
 mirrors/generic_interface_test/none: Fail # Inexpressible in multitest
 
 [ $compiler == none && $runtime == dartium ]
 async/schedule_microtask5_test: Pass, Timeout # Issue 13719: Please triage this failure.
 async/timer_cancel2_test: Pass, Timeout # Issue 13719: Please triage this failure.
 
 [ $runtime != none ]
 async/schedule_microtask_test: Fail # Issue 9001, Issue 9002