Error:

[ RUN      ] SelectToSpeakTest.SmoothlyReadsAcrossFormattedText
[8128:8128:0329/060203.794267:WARNING:chrome_browser_main_chromeos.cc(618)] Running as stub user with profile dir: test-user
[8128:8128:0329/060203.839768:WARNING:user_session_manager.cc(1068)] Attempting to save user password for non enterprise user.
[8128:8128:0329/060203.884148:ERROR:network_type_pattern.cc(134)] NetworkTypePattern: wifi: Can not match empty type.
[8128:8128:0329/060203.884239:ERROR:network_type_pattern.cc(134)] NetworkTypePattern: wifi: Can not match empty type.
[8128:8128:0329/060203.884301:ERROR:network_type_pattern.cc(134)] NetworkTypePattern: wifi: Can not match empty type.
[8128:8128:0329/060203.884317:ERROR:network_type_pattern.cc(134)] NetworkTypePattern: wifi: Can not match empty type.
ALSA lib confmisc.c:768:(parse_card) cannot find card '0'
ALSA lib conf.c:4248:(_snd_config_evaluate) function snd_func_card_driver returned error: No such file or directory
ALSA lib confmisc.c:392:(snd_func_concat) error evaluating strings
ALSA lib conf.c:4248:(_snd_config_evaluate) function snd_func_concat returned error: No such file or directory
ALSA lib confmisc.c:1251:(snd_func_refer) error evaluating name
ALSA lib conf.c:4248:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:4727:(snd_config_expand) Evaluate error: No such file or directory
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM default
[8128:8154:0329/060204.073714:WARNING:alsa_util.cc(24)] PcmOpen: default,No such file or directory
ALSA lib confmisc.c:768:(parse_card) cannot find card '0'
ALSA lib conf.c:4248:(_snd_config_evaluate) function snd_func_card_driver returned error: No such file or directory
ALSA lib confmisc.c:392:(snd_func_concat) error evaluating strings
ALSA lib conf.c:4248:(_snd_config_evaluate) function snd_func_concat returned error: No such file or directory
ALSA lib confmisc.c:1251:(snd_func_refer) error evaluating name
ALSA lib conf.c:4248:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:4727:(snd_config_expand) Evaluate error: No such file or directory
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM default
[8128:8154:0329/060204.073871:WARNING:alsa_util.cc(24)] PcmOpen: plug:default,No such file or directory
[8128:8128:0329/060204.116110:INFO:speech_monitor.cc(112)] Speaking This is some text  with a node  in the middle 
[8128:8160:0329/060204.134379:ERROR:x11_util.cc(90)] X IO error received (X server probably went away)
[1/1] SelectToSpeakTest.SmoothlyReadsAcrossFormattedText (CRASHED)
1 test crashed:
    SelectToSpeakTest.SmoothlyReadsAcrossFormattedText (../../chrome/browser/chromeos/accessibility/select_to_speak_browsertest.cc:157)
[1/1] SelectToSpeakTest.SmoothlyReadsAcrossFormattedText (454 ms)
SUCCESS: all tests passed.
Summary of all test iterations:
1 test crashed:
    SelectToSpeakTest.SmoothlyReadsAcrossFormattedText (../../chrome/browser/chromeos/accessibility/select_to_speak_browsertest.cc:157)
End of the summary.

Seems like it was crashing because there was an X11 error. Culprit CL doesn't seem related. 

Flakiness dashboard is now green: https://test-results.appspot.com/dashboards/flakiness_dashboard.html#testType=interactive_ui_tests&tests=SmoothlyReadsAcrossFormattedText

Thanks for marking this as incorrect, we'll investigate this at our next triage.