webkit_layout_tests failing on chromium.webkit/WebKit Linux Trusty (dbg)

Builders failed on: 
- WebKit Linux Trusty (dbg): 
  https://build.chromium.org/p/chromium.webkit/builders/WebKit%20Linux%20Trusty%20%28dbg%29

From https://chromium-swarm.appspot.com/task?id=39612540c0e0dc10&refresh=10&show_raw=1:

01:33:49.042 799 worker/2 media/controls/overflow-menu-always-visible.html output stderr lines:
01:33:49.042 799   
01:33:49.042 799   DevTools listening on ws://127.0.0.1:49502/devtools/browser/0c7f5e2c-e455-4447-9216-0b9c2e2773fe
01:33:49.042 799   Xlib:  extension "RANDR" missing on display ":100".
01:33:49.042 799   [904:904:1023/013345.714016:30539468654:ERROR:gpu_info.cc(103)] No active GPU found, returning primary GPU.
01:33:49.042 799   ALSA lib confmisc.c:768:(parse_card) cannot find card '0'
01:33:49.042 799   ALSA lib conf.c:4248:(_snd_config_evaluate) function snd_func_card_driver returned error: No such file or directory
01:33:49.042 799   ALSA lib confmisc.c:392:(snd_func_concat) error evaluating strings
01:33:49.042 799   ALSA lib conf.c:4248:(_snd_config_evaluate) function snd_func_concat returned error: No such file or directory
01:33:49.042 799   ALSA lib confmisc.c:1251:(snd_func_refer) error evaluating name
01:33:49.042 799   ALSA lib conf.c:4248:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
01:33:49.042 799   ALSA lib conf.c:4727:(snd_config_expand) Evaluate error: No such file or directory
01:33:49.042 799   ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM default
01:33:49.042 799   [805:894:1023/013346.441421:30540196057:WARNING:alsa_util.cc(24)] PcmOpen: default,No such file or directory
01:33:49.042 799   ALSA lib confmisc.c:768:(parse_card) cannot find card '0'
01:33:49.042 799   ALSA lib conf.c:4248:(_snd_config_evaluate) function snd_func_card_driver returned error: No such file or directory
01:33:49.042 799   ALSA lib confmisc.c:392:(snd_func_concat) error evaluating strings
01:33:49.042 799   ALSA lib conf.c:4248:(_snd_config_evaluate) function snd_func_concat returned error: No such file or directory
01:33:49.042 799   ALSA lib confmisc.c:1251:(snd_func_refer) error evaluating name
01:33:49.042 799   ALSA lib conf.c:4248:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
01:33:49.042 799   ALSA lib conf.c:4727:(snd_config_expand) Evaluate error: No such file or directory
01:33:49.042 799   ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM default
01:33:49.042 799   [805:894:1023/013346.441990:30540196612:WARNING:alsa_util.cc(24)] PcmOpen: plug:default,No such file or directory
01:33:49.042 799   [805:894:1023/013346.442189:30540196810:ERROR:audio_output_resampler.cc(396)] Unable to open audio device in high latency mode.  Falling back to fake audio output.
01:33:49.273 799 "/b/s/w/ir/out/Debug/image_diff --diff /b/s/w/itGMK4rK/tmpM8NzSj/actual.png /b/s/w/itGMK4rK/tmpM8NzSj/expected.png /b/s/w/itGMK4rK/tmpM8NzSj/diff.png" took 0.23s
01:33:49.500 799 "/b/s/w/ir/out/Debug/image_diff --diff /b/s/w/itGMK4rK/tmpKUmm13/actual.png /b/s/w/itGMK4rK/tmpKUmm13/expected.png /b/s/w/itGMK4rK/tmpKUmm13/diff.png" took 0.23s
01:33:49.504 18003 [3/3] media/controls/overflow-menu-always-visible.html failed unexpectedly (reference mismatch)
01:33:49.502 799 worker/2 media/controls/overflow-menu-always-visible.html failed:
01:33:49.502 799 worker/2  reference mismatch
01:33:49.503 799 worker/2 killing secondary driver
01:33:49.503 799 worker/2 exiting
01:33:49.503 799 worker/2 cleaning up
01:33:49.503 799 worker/2 killing primary driver
01:33:49.503 799 killed pid 805
01:33:49.503 799 worker/2 killing secondary driver
01:33:49.504 18003 worker/2 cleaning up
01:33:49.504 18003 worker/2 cleaning up
01:33:49.507 18003 
01:33:49.507 18003 Retrying 1 unexpected failure, attempt 2 of 3...
01:33:49.508 18003 Sharding tests ...
01:33:49.508 18003 Starting 1 worker ...
01:33:49.508 18003 worker/0 starting
01:33:55.586 18003 worker/0 media/controls/overflow-menu-always-visible.html output stderr lines:
01:33:55.587 18003   
01:33:55.587 18003   DevTools listening on ws://127.0.0.1:47572/devtools/browser/4f05128e-a78a-4209-a130-4033cd787576
01:33:55.587 18003   Xlib:  extension "RANDR" missing on display ":100".
01:33:55.587 18003   [1091:1091:1023/013352.418057:30546172689:ERROR:gpu_info.cc(103)] No active GPU found, returning primary GPU.
01:33:55.587 18003   ALSA lib confmisc.c:768:(parse_card) cannot find card '0'
01:33:55.587 18003   ALSA lib conf.c:4248:(_snd_config_evaluate) function snd_func_card_driver returned error: No such file or directory
01:33:55.587 18003   ALSA lib confmisc.c:392:(snd_func_concat) error evaluating strings
01:33:55.587 18003   ALSA lib conf.c:4248:(_snd_config_evaluate) function snd_func_concat returned error: No such file or directory
01:33:55.587 18003   ALSA lib confmisc.c:1251:(snd_func_refer) error evaluating name
01:33:55.587 18003   ALSA lib conf.c:4248:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
01:33:55.587 18003   ALSA lib conf.c:4727:(snd_config_expand) Evaluate error: No such file or directory
01:33:55.587 18003   ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM default
01:33:55.588 18003   [1052:1089:1023/013352.525914:30546280550:WARNING:alsa_util.cc(24)] PcmOpen: default,No such file or directory
01:33:55.588 18003   ALSA lib confmisc.c:768:(parse_card) cannot find card '0'
01:33:55.588 18003   ALSA lib conf.c:4248:(_snd_config_evaluate) function snd_func_card_driver returned error: No such file or directory
01:33:55.588 18003   ALSA lib confmisc.c:392:(snd_func_concat) error evaluating strings
01:33:55.588 18003   ALSA lib conf.c:4248:(_snd_config_evaluate) function snd_func_concat returned error: No such file or directory
01:33:55.588 18003   ALSA lib confmisc.c:1251:(snd_func_refer) error evaluating name
01:33:55.588 18003   ALSA lib conf.c:4248:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
01:33:55.588 18003   ALSA lib conf.c:4727:(snd_config_expand) Evaluate error: No such file or directory
01:33:55.588 18003   ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM default
01:33:55.588 18003   [1052:1089:1023/013352.526785:30546281411:WARNING:alsa_util.cc(24)] PcmOpen: plug:default,No such file or directory
01:33:55.588 18003   [1052:1089:1023/013352.527097:30546281721:ERROR:audio_output_resampler.cc(396)] Unable to open audio device in high latency mode.  Falling back to fake audio output.
01:33:55.816 18003 "/b/s/w/ir/out/Debug/image_diff --diff /b/s/w/itGMK4rK/tmpgeIBc1/actual.png /b/s/w/itGMK4rK/tmpgeIBc1/expected.png /b/s/w/itGMK4rK/tmpgeIBc1/diff.png" took 0.23s
01:33:56.046 18003 "/b/s/w/ir/out/Debug/image_diff --diff /b/s/w/itGMK4rK/tmpvUC6r1/actual.png /b/s/w/itGMK4rK/tmpvUC6r1/expected.png /b/s/w/itGMK4rK/tmpvUC6r1/diff.png" took 0.23s
01:33:56.047 18003 [1/1] media/controls/overflow-menu-always-visible.html failed unexpectedly (reference mismatch)
01:33:56.047 18003 worker/0 media/controls/overflow-menu-always-visible.html failed:
01:33:56.047 18003 worker/0  reference mismatch
01:33:56.047 18003 worker/0 killing secondary driver
01:33:56.048 18003 worker/0 exiting
01:33:56.048 18003 worker/0 cleaning up
01:33:56.048 18003 worker/0 killing primary driver
01:33:56.048 18003 killed pid 1052
01:33:56.048 18003 worker/0 killing secondary driver
01:33:56.049 18003