timeout_pass_test is flaky #18507

⏩ RUNNING: cd dev\automated_tests; ..\..\bin\flutter.bat test test_smoke_test\timeout_pass_test.dart
00:11 +0: flutter_test timeout logic - addTime - positive                                                                                                                                              
══╡ EXCEPTION CAUGHT BY FLUTTER TEST FRAMEWORK ╞════════════════════════════════════════════════════
The following TimeoutException was thrown running a test:
TimeoutException after 0:00:04.000000: The test exceeded the timeout. It may have hung.
Consider using "addTime" to increase the timeout before expensive operations.
When the exception was thrown, this was the stack:
#2      AutomatedTestWidgetsFlutterBinding._checkTimeout (package:flutter_test/src/binding.dart:786:25)
#16     _Timer._runTimers (dart:isolate/runtime/libtimer_impl.dart:382:19)
#17     _Timer._handleMessage (dart:isolate/runtime/libtimer_impl.dart:416:5)
#18     _RawReceivePortImpl._handleMessage (dart:isolate/runtime/libisolate_patch.dart:165:12)
#22     AutomatedTestWidgetsFlutterBinding.runTest (package:flutter_test/src/binding.dart:836:25)
#23     testWidgets.<anonymous closure> (package:flutter_test/src/widget_tester.dart:65:22)
#24     Declarer.test.<anonymous closure>.<anonymous closure>.<anonymous closure> (package:test/src/backend/declarer.dart:161:27)
#27     Declarer.test.<anonymous closure>.<anonymous closure>.<anonymous closure> (package:test/src/backend/declarer.dart:0:0)
#28     Invoker.waitForOutstandingCallbacks.<anonymous closure> (package:test/src/backend/invoker.dart:249:15)
#33     Invoker.waitForOutstandingCallbacks.<anonymous closure> (package:test/src/backend/invoker.dart:246:14)
#38     Invoker.waitForOutstandingCallbacks (package:test/src/backend/invoker.dart:246:5)
#39     Declarer.test.<anonymous closure>.<anonymous closure> (package:test/src/backend/declarer.dart:159:33)
#44     Declarer.test.<anonymous closure> (package:test/src/backend/declarer.dart:158:13)
#49     Declarer.test.<anonymous closure> (package:test/src/backend/declarer.dart:143:57)
#50     Invoker._onRun.<anonymous closure>.<anonymous closure>.<anonymous closure>.<anonymous closure> (package:test/src/backend/invoker.dart:403:25)
#55     Invoker._onRun.<anonymous closure>.<anonymous closure>.<anonymous closure>.<anonymous closure> (package:test/src/backend/invoker.dart:402:22)
#69     _Timer._runTimers (dart:isolate/runtime/libtimer_impl.dart:382:19)
#70     _Timer._handleMessage (dart:isolate/runtime/libtimer_impl.dart:416:5)
#71     _RawReceivePortImpl._handleMessage (dart:isolate/runtime/libisolate_patch.dart:165:12)
#77     Invoker._onRun.<anonymous closure>.<anonymous closure>.<anonymous closure> (package:test/src/backend/invoker.dart:402:15)
#82     Invoker._onRun.<anonymous closure>.<anonymous closure>.<anonymous closure> (package:test/src/backend/invoker.dart:389:18)
#87     Invoker._onRun.<anonymous closure>.<anonymous closure> (package:test/src/backend/invoker.dart:389:9)
#88     Invoker._guardIfGuarded (package:test/src/backend/invoker.dart:443:15)
#89     Invoker._onRun.<anonymous closure> (package:test/src/backend/invoker.dart:388:7)
#96     Invoker._onRun (package:test/src/backend/invoker.dart:387:11)
#97     LiveTestController._run (package:test/src/backend/live_test_controller.dart:188:5)
#98     _LiveTest.run (package:test/src/backend/live_test_controller.dart:40:31)
#99     RemoteListener._runLiveTest.<anonymous closure> (package:test/src/runner/remote_listener.dart:257:16)
#104    RemoteListener._runLiveTest (package:test/src/runner/remote_listener.dart:256:5)
#105    RemoteListener._serializeTest.<anonymous closure> (package:test/src/runner/remote_listener.dart:209:7)
#123    _GuaranteeSink.add (package:stream_channel/src/guarantee_channel.dart:121:12)
#124    new _MultiChannel.<anonymous closure> (package:stream_channel/src/multi_channel.dart:154:31)
#150    new _WebSocketImpl._fromSocket.<anonymous closure> (dart:_http/websocket_impl.dart:1128:21)
#156    _WebSocketProtocolTransformer._messageFrameEnd (dart:_http/websocket_impl.dart:334:22)
#157    _WebSocketProtocolTransformer.add (dart:_http/websocket_impl.dart:229:46)
#165    _Socket._onData (dart:io/runtime/binsocket_patch.dart:1672:41)
#172    new _RawSocket.<anonymous closure> (dart:io/runtime/binsocket_patch.dart:1245:33)
#173    _NativeSocket.issueReadEvent.issue (dart:io/runtime/binsocket_patch.dart:797:14)
(elided 137 frames from package dart:async and package stack_trace)
The test description was:
flutter_test timeout logic - addTime - positive
════════════════════════════════════════════════════════════════════════════════════════════════════
00:11 +0 -1: flutter_test timeout logic - addTime - positive [E]                                                                                                                                       
  Test failed. See exception logs above.
  The test description was: flutter_test timeout logic - addTime - positive
  
══╡ EXCEPTION CAUGHT BY FLUTTER TEST FRAMEWORK ╞════════════════════════════════════════════════════
The following assertion was thrown running a test (but after the test had completed):
'package:flutter_test/src/binding.dart': Failed assertion: line 872 pos 12: '_currentFakeAsync !=
null': is not true.
Either the assertion indicates an error in the framework itself, or we should provide substantially
more information in this error message to help you determine and fix the underlying cause.
In either case, please report this assertion by filing a bug on GitHub:
  https://github.com/flutter/flutter/issues/new
When the exception was thrown, this was the stack:
00:11 +0 -1: Some tests failed.                                                                                                                                                                        
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
ERROR: Last command exited with 1 (expected: zero).
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