Seen here:
https://ci.chromium.org/buildbot/tryserver.chromium.chromiumos/linux-chromeos-rel/66603

on an unrelated CL. Log:

[ RUN      ] TrayAccessibilityTestInstance/TrayAccessibilityTest.CheckMenuVisibilityOnDetailMenu/1
[12972:12972:0223/123548.008655:WARNING:chrome_browser_main_chromeos.cc(613)] Running as stub user with profile dir: test-user
[12972:13089:0223/123548.546625:ERROR:logging_chrome.cc(218)] Unable to create symlink /b/s/w/it6BjSHx/.org.chromium.Chromium.7twMjL/dc9dlqX/test-user/chrome_debug.log pointing at /b/s/w/it6BjSHx/.org.chromium.Chromium.7twMjL/dc9dlqX/test-user/chrome_debug_20180223-123548: No such file or directory (2)
[12972:12972:0223/123548.595503:WARNING:user_session_manager.cc(1052)] Attempting to save user password for non enterprise user.
[12972:12972:0223/123548.699961:ERROR:network_type_pattern.cc(134)] NetworkTypePattern: wifi: Can not match empty type.
[12972:12972:0223/123548.700368:ERROR:network_type_pattern.cc(134)] NetworkTypePattern: wifi: Can not match empty type.
[12972:12972:0223/123548.700802:ERROR:network_type_pattern.cc(134)] NetworkTypePattern: wifi: Can not match empty type.
[12972:12972:0223/123548.700876:ERROR:network_type_pattern.cc(134)] NetworkTypePattern: wifi: Can not match empty type.
[12972:12972:0223/123548.762399:ERROR:wallpaper_controller.cc(1264)] User is ephemeral or guest! Fallback to default wallpaper.
../../chrome/browser/chromeos/system/tray_accessibility_browsertest.cc:1681: Failure
Value of: IsHelpAvailableOnDetailMenu()
  Actual: false
Expected: true
[12972:12972:0223/123549.016245:INFO:chrome_cryptauth_service.cc(240)] Refresh token not yet available; waiting before starting CryptAuth managers.
[12972:12972:0223/123549.032531:WARNING:pref_notifier_impl.cc(28)] Init observer found at shutdown.
[12972:12972:0223/123549.033292:WARNING:url_request_context_getter.cc(43)] URLRequestContextGetter leaking due to no owning thread.
[12972:12972:0223/123549.033310:WARNING:url_request_context_getter.cc(43)] URLRequestContextGetter leaking due to no owning thread.
[  FAILED  ] TrayAccessibilityTestInstance/TrayAccessibilityTest.CheckMenuVisibilityOnDetailMenu/1, where GetParam() = 1 (1181 ms)