Findit identified the culprit r579403 with confidence 70.0% in the config "chromium.chromiumos / linux-chromeos-rel"
based on the flakiness trend:

https://findit-for-me.appspot.com/waterfall/flake?key=ag9zfmZpbmRpdC1mb3ItbWVy-wELEhdNYXN0ZXJGbGFrZUFuYWx5c2lzUm9vdCLEAWNocm9taXVtLmNocm9taXVtb3MvbGludXgtY2hyb21lb3MtcmVsLzExNzY4L21hc2hfYnJvd3Nlcl90ZXN0cy9RV3hzTDFCaGMzTjNiM0prVFdGdVlXZGxja0p5YjNkelpYSlVaWE4wVjJsMGFGWnBaWGR6Um1WaGRIVnlaUzVRY205dGNIUkdiM0pHWlhSamFGTjFZbTFwZEZkcGRHaHZkWFJPWVhacFoyRjBhVzl1WDFOcFoyNTFjRVp2Y20wdk1BPT0MCxITTWFzdGVyRmxha2VBbmFseXNpcxgBDA

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%20All/PasswordManagerBrowserTestWithViewsFeature.PromptForFetchSubmitWithoutNavigation_SignupForm/0&comment=Link%20to%20Analysis%3A%20https://findit-for-me.appspot.com/waterfall/flake?key=ag9zfmZpbmRpdC1mb3ItbWVy-wELEhdNYXN0ZXJGbGFrZUFuYWx5c2lzUm9vdCLEAWNocm9taXVtLmNocm9taXVtb3MvbGludXgtY2hyb21lb3MtcmVsLzExNzY4L21hc2hfYnJvd3Nlcl90ZXN0cy9RV3hzTDFCaGMzTjNiM0prVFdGdVlXZGxja0p5YjNkelpYSlVaWE4wVjJsMGFGWnBaWGR6Um1WaGRIVnlaUzVRY205dGNIUkdiM0pHWlhSamFGTjFZbTFwZEZkcGRHaHZkWFJPWVhacFoyRjBhVzl1WDFOcFoyNTFjRVp2Y20wdk1BPT0MCxITTWFzdGVyRmxha2VBbmFseXNpcxgBDA

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

Sample failure:

../../chrome/browser/password_manager/password_manager_browsertest.cc:868: Failure
Value of: prompt_observer->IsSavePromptShownAutomatically()
  Actual: false
Expected: true
Stack trace:
#0 0x000001ffac7c testing::internal::UnitTestImpl::CurrentOsStackTraceExceptTop()
#1 0x000001ffa659 testing::internal::AssertHelper::operator=()
#2 0x000000a369ff password_manager::PasswordManagerBrowserTestWithViewsFeature_PromptForFetchSubmitWithoutNavigation_SignupForm_Test::RunTestOnMainThread()
#3 0x00000414c17b content::BrowserTestBase::ProxyRunTestOnMainThreadLoop()
#4 0x000003d5c1fa ChromeBrowserMainParts::PreMainMessageLoopRunImpl()
#5 0x000003d5b141 ChromeBrowserMainParts::PreMainMessageLoopRun()
#6 0x000001c14ac5 chromeos::ChromeBrowserMainPartsChromeos::PreMainMessageLoopRun()
#7 0x00000296c4e1 content::BrowserMainLoop::PreMainMessageLoopRun()
#8 0x000002cd0e67 content::StartupTaskRunner::RunAllTasksNow()
#9 0x00000296aecd content::BrowserMainLoop::CreateStartupTasks()
#10 0x00000296e7a3 content::BrowserMainRunnerImpl::Initialize()
#11 0x000002968ed4 content::BrowserMain()
#12 0x000003b9f07c content::ContentMainRunnerImpl::Run()
#13 0x0000057b21c0 service_manager::Main()
#14 0x000003b9d344 content::ContentMain()
#15 0x00000414bdb2 content::BrowserTestBase::SetUp()
#16 0x000003d0b7f2 InProcessBrowserTest::SetUp()

Appears to be a dupe.  Will disable the test.