Findit identified the culprit r568300 with confidence 100.0% in the config "chromium.chromiumos / linux-chromeos-rel"
based on the flakiness trend:

https://findit-for-me.appspot.com/waterfall/flake?key=ag9zfmZpbmRpdC1mb3ItbWVy3QELEhdNYXN0ZXJGbGFrZUFuYWx5c2lzUm9vdCKmAWNocm9taXVtLmNocm9taXVtb3MvbGludXgtY2hyb21lb3MtcmVsLzk3NDQvdml6X2Jyb3dzZXJfdGVzdHMvVTJWeWRtbGpaVmR2Y210bGNsUmxjM1JYYVhSb1RtRjBhWFpsUW1sdVpHbHVaM012VTJWeWRtbGpaVmR2Y210bGNrSmhjMlZrUW1GamEyZHliM1Z1WkZSbGMzUXVRbUZ6YVdNdk1BPT0MCxITTWFzdGVyRmxha2VBbmFseXNpcxgBDA

If the culprit above is wrong, please file a bug using this link and hit submit:
https://bugs.chromium.org/p/chromium/issues/entry?status=Unconfirmed&labels=Pri-1,Test-Findit-Wrong&components=Tools%3ETest%3EFindit%3EFlakiness&summary=%5BFindit%5D%20Flake%20Analyzer%20-%20Wrong%20result%20for%20ServiceWorkerTestWithNativeBindings/ServiceWorkerBasedBackgroundTest.Basic/0&comment=Link%20to%20Analysis%3A%20https://findit-for-me.appspot.com/waterfall/flake?key=ag9zfmZpbmRpdC1mb3ItbWVy3QELEhdNYXN0ZXJGbGFrZUFuYWx5c2lzUm9vdCKmAWNocm9taXVtLmNocm9taXVtb3MvbGludXgtY2hyb21lb3MtcmVsLzk3NDQvdml6X2Jyb3dzZXJfdGVzdHMvVTJWeWRtbGpaVmR2Y210bGNsUmxjM1JYYVhSb1RtRjBhWFpsUW1sdVpHbHVaM012VTJWeWRtbGpaVmR2Y210bGNrSmhjMlZrUW1GamEyZHliM1Z1WkZSbGMzUXVRbUZ6YVdNdk1BPT0MCxITTWFzdGVyRmxha2VBbmFseXNpcxgBDA

Automatically posted by the findit-for-me app (https://goo.gl/Ot9f7N).

Despite my best efforts, it seems the newly added test is flaky.

Tests are timing out occasionally, logs below. Will take a look. 


[1/2] ServiceWorkerTestWithNativeBindings/ServiceWorkerBasedBackgroundTest.PRE_Basic/0 (652 ms)
Still waiting for the following processes to finish:
	./browser_tests --brave-new-test-launcher --cfi-diag=0 --enable-features=VizDisplayCompositor --gtest_also_run_disabled_tests --gtest_filter=ServiceWorkerTestWithNativeBindings/ServiceWorkerBasedBackgroundTest.Basic/0 --single_process --test-launcher-bot-mode --test-launcher-output=/b/s/w/itQwu9Gh/.org.chromium.Chromium.4g1Vve/resultsJPisVJ/test_results.xml --test-launcher-retry-limit=0 --test-launcher-summary-output=/b/s/w/ioyRoQkD/output.json --user-data-dir=/b/s/w/itQwu9Gh/.org.chromium.Chromium.4g1Vve/dsvN5W8
Still waiting for the following processes to finish:
	./browser_tests --brave-new-test-launcher --cfi-diag=0 --enable-features=VizDisplayCompositor --gtest_also_run_disabled_tests --gtest_filter=ServiceWorkerTestWithNativeBindings/ServiceWorkerBasedBackgroundTest.Basic/0 --single_process --test-launcher-bot-mode --test-launcher-output=/b/s/w/itQwu9Gh/.org.chromium.Chromium.4g1Vve/resultsJPisVJ/test_results.xml --test-launcher-retry-limit=0 --test-launcher-summary-output=/b/s/w/ioyRoQkD/output.json --user-data-dir=/b/s/w/itQwu9Gh/.org.chromium.Chromium.4g1Vve/dsvN5W8
[ RUN      ] ServiceWorkerTestWithNativeBindings/ServiceWorkerBasedBackgroundTest.Basic/0
[29009:29009:0622/151428.083894:ERROR:display_color_manager.cc(276)] Display ID: 2200000000 cannot be found.
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
[29009:29035:0622/151428.097695: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
[29009:29035:0622/151428.097812:WARNING:alsa_util.cc(24)] PcmOpen: plug:default,No such file or directory
[29009:29009:0622/151428.223757:ERROR:display_color_manager.cc(276)] Display ID: 2200000000 cannot be found.
[29009:29009:0622/151428.290319:ERROR:display_color_manager.cc(276)] Display ID: 2200000000 cannot be found.
[29009:29097:0622/151428.293894:WARNING:embedded_test_server.cc(229)] Request not handled. Returning 404: /favicon.ico
BrowserTestBase received signal: Terminated. Backtrace:
#0 0x000003b3803c base::debug::StackTrace::StackTrace()
#1 0x000003fbdf85 content::(anonymous namespace)::DumpStackTraceSignalHandler()
#2 0x7f142d854cb0 <unknown>
#3 0x7f142d91c6d3 epoll_wait
#4 0x00000451781d epoll_dispatch
#5 0x0000045152fc event_base_loop
#6 0x000003b47681 base::MessagePumpLibevent::Run()
#7 0x000003af3df5 base::RunLoop::Run()
#8 0x000007d5c477 ExtensionTestMessageListener::WaitUntilSatisfied()
#9 0x0000012d7946 extensions::ServiceWorkerBasedBackgroundTest_Basic_Test::RunTestOnMainThread()
#10 0x000003fbd5f3 content::BrowserTestBase::ProxyRunTestOnMainThreadLoop()
#11 0x000003bd8898 ChromeBrowserMainParts::PreMainMessageLoopRunImpl()
#12 0x000003bd77fa ChromeBrowserMainParts::PreMainMessageLoopRun()
#13 0x000001a92e71 chromeos::ChromeBrowserMainPartsChromeos::PreMainMessageLoopRun()
#14 0x0000027c9731 content::BrowserMainLoop::PreMainMessageLoopRun()
#15 0x000002b21847 content::StartupTaskRunner::RunAllTasksNow()
#16 0x0000027c80d2 content::BrowserMainLoop::CreateStartupTasks()
#17 0x0000027cb9d5 content::BrowserMainRunnerImpl::Initialize()
#18 0x0000027c602c content::BrowserMain()
#19 0x000003a6b4ab content::ContentMainRunnerImpl::Run()
#20 0x00000559ab1f service_manager::Main()
#21 0x000003a69654 content::ContentMain()
#22 0x000003fbd20f content::BrowserTestBase::SetUp()
#23 0x000003b9a6e2 InProcessBrowserTest::SetUp()
#24 0x0000012e918f extensions::ServiceWorkerTest::SetUp()
#25 0x000001e6deed testing::Test::Run()
#26 0x000001e6eb10 testing::TestInfo::Run()
#27 0x000001e6f027 testing::TestCase::Run()
#28 0x000001e7a507 testing::internal::UnitTestImpl::RunAllTests()
#29 0x000001e7a07d testing::UnitTest::Run()
#30 0x000003baedb1 base::TestSuite::Run()
#31 0x000003ab9045 ChromeTestSuiteRunner::RunTestSuite()
#32 0x000003fdb439 content::LaunchTests()
#33 0x000003ab9503 LaunchChromeTests()
#34 0x000003ab8fde main
#35 0x7f142d83ff45 __libc_start_main
#36 0x0000005f21aa _start
[2/2] ServiceWorkerTestWithNativeBindings/ServiceWorkerBasedBackgroundTest.Basic/0 (TIMED OUT)
1 test timed out:
    ServiceWorkerTestWithNativeBindings/ServiceWorkerBasedBackgroundTest.Basic/0 (../../chrome/browser/extensions/service_worker_apitest.cc:268)

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b71a317e3c92bb3886310560d0589cec867d7450

commit b71a317e3c92bb3886310560d0589cec867d7450
Author: Greg Thompson <grt@chromium.org>
Date: Wed Jun 27 12:29:17 2018

Disable ServiceWorkerBasedBackgroundTest.Basic due to flakes.

BUG= 855800 
TBR=lazyboy@chromium.org
NOTRY=true

Change-Id: I5eb0663724303fd7f7f2eb4b0feac36c82cc4421
Reviewed-on: https://chromium-review.googlesource.com/1116796
Reviewed-by: Greg Thompson <grt@chromium.org>
Commit-Queue: Greg Thompson <grt@chromium.org>
Cr-Commit-Position: refs/heads/master@{#570739}
[modify] https://crrev.com/b71a317e3c92bb3886310560d0589cec867d7450/chrome/browser/extensions/service_worker_apitest.cc

Removing Sheriff-Chromium since the test is now disabled and the fix is being worked on.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/ad376e6b7757ca11359d282acb2c3ccfdb600e69

commit ad376e6b7757ca11359d282acb2c3ccfdb600e69
Author: Istiaque Ahmed <lazyboy@chromium.org>
Date: Thu Sep 13 22:48:25 2018

[Extensions] Enable ServiceWorkerBasedBackgroundTest.Basic.

The root cause is fixed by
https://crrev.com/b8e24bdbf6bbe43bc32fd684f2a0aad914e804d2
and the test doesn't flake locally or on trybots anymore.

Bug:  855800 
Change-Id: I316b876de5e993f1d41bb12cc040ac9e1dccd0e0
Reviewed-on: https://chromium-review.googlesource.com/1226071
Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
Commit-Queue: Istiaque Ahmed <lazyboy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#591188}
[modify] https://crrev.com/ad376e6b7757ca11359d282acb2c3ccfdb600e69/chrome/browser/extensions/service_worker_apitest.cc