The SpeechRecognizerImplTest tests in speech_recognizer_impl_unittest.cc have gotten flaky lately in Linux ChromiumOS Tests (https://build.chromium.org/p/chromium.chromiumos/builders/Linux%20ChromiumOS%20Tests%20%281%29).  

The tests almost always pass on the second try, and have only caused 2 build failures in the last three days.  I'm not familiar with this code, but things seemed fine 4 days ago, and https://codereview.chromium.org/2675713002 was landed three days ago.  Maybe just a coincidence, but "Switch Speech Recognition to asynchronous" and tests starting to flake seem like they could be related.  In any case, olka@, would you mind taking a look at this?


Examples from the last 15 builds:

Builds #33447, 33446, 33439, 33434, 33433
[ RUN      ] SpeechRecognizerImplTest.StartNoInputDevices
../../content/browser/speech/speech_recognizer_impl_unittest.cc:250: Failure
Value of: error_
  Actual: 0
Expected: SPEECH_RECOGNITION_ERROR_AUDIO_CAPTURE
Which is: 3
../../content/browser/speech/speech_recognizer_impl_unittest.cc:111: Failure
Value of: recognition_started_ ^ recognition_ended_
  Actual: true
Expected: false
[  FAILED  ] SpeechRecognizerImplTest.StartNoInputDevices (1 ms)


Build #33446
[ RUN      ] SpeechRecognizerImplTest.CancelNoData
../../content/browser/speech/speech_recognizer_impl_unittest.cc:335: Failure
Value of: error_
  Actual: 0
Expected: SPEECH_RECOGNITION_ERROR_ABORTED
Which is: 2
[  FAILED  ] SpeechRecognizerImplTest.CancelNoData (1 ms)


Builds #33445, 33443
[ RUN      ] SpeechRecognizerImplTest.ConnectionError
[7708:7708:0209/085512.602253:26333758638:WARNING:audio_manager.cc(321)] Multiple instances of AudioManager detected
../../content/browser/speech/speech_recognizer_impl_unittest.cc:433: Failure
Value of: controller
  Actual: false
Expected: true
[  FAILED  ] SpeechRecognizerImplTest.ConnectionError (0 ms)


Build #33435
[ RUN      ] SpeechRecognizerImplTest.CancelWithData
[15141:15141:0209/050624.843591:519050090:WARNING:audio_manager.cc(321)] Multiple instances of AudioManager detected
../../content/browser/speech/speech_recognizer_impl_unittest.cc:411: Failure
Value of: controller
  Actual: false
Expected: true
[  FAILED  ] SpeechRecognizerImplTest.CancelWithData (0 ms)