Findit identified the culprit r565609 with confidence 70.0% in the config "chromium.memory / Linux Chromium OS ASan LSan Tests (1)"
based on the flakiness trend:

https://findit-for-me.appspot.com/waterfall/flake?key=ag9zfmZpbmRpdC1mb3ItbWVywQELEhdNYXN0ZXJGbGFrZUFuYWx5c2lzUm9vdCKKAWNocm9taXVtLm1lbW9yeS9MaW51eCBDaHJvbWl1bSBPUyBBU2FuIExTYW4gVGVzdHMgKDEpLzI3ODI2L2Jyb3dzZXJfdGVzdHMvU0c5emRHVmtRWEJ3VkdWemRDNVRhRzkxYkdSVGFHOTNURzlqWVhScGIyNUNZWEpFWVc1blpYSnZkWE12TVE9PQwLEhNNYXN0ZXJGbGFrZUFuYWx5c2lzGAEM


Automatically posted by the findit-for-me app (https://goo.gl/Ot9f7N).
Feedback is welcome! Please use component Tools>Test>FindIt>Flakiness

Detected 3 new flakes for test/step "HostedAppTest.ShouldShowLocationBarDangerous/1". To see the actual flakes, please visit https://chromium-try-flakes.appspot.com/all_flake_occurrences?key=ahVzfmNocm9taXVtLXRyeS1mbGFrZXNyOQsSBUZsYWtlIi5Ib3N0ZWRBcHBUZXN0LlNob3VsZFNob3dMb2NhdGlvbkJhckRhbmdlcm91cy8xDA. This message was posted automatically by the chromium-try-flakes app.

Reverting at https://chromium-review.googlesource.com/c/chromium/src/+/1094955

Tests still appear to be flaky: https://test-results.appspot.com/dashboards/flakiness_dashboard.html#tests=HostedAppTest.ShouldShowLocationBarDangerous

Preparing a CL to disable them.

 Issue 851225  has been merged into this issue.

Assigning bug to ortuno@ (author of the initial test) for triaging/test fixing.

Double-checking the flakiness dashboard, it looks like the revert of the Findit identified CL did indeed fix the issue (it just took a very long time for all bots to pick up and run the patch). Holding back the revert (https://chromium-review.googlesource.com/c/chromium/src/+/1095190).

tests are de-flaked; no need to disable the tests.

Findit identified the culprit r565609 with confidence 70.0% in the config "chromium.memory / Linux Chromium OS ASan LSan Tests (1)"
based on the flakiness trend:

https://findit-for-me.appspot.com/waterfall/flake?key=ag9zfmZpbmRpdC1mb3ItbWVywQELEhdNYXN0ZXJGbGFrZUFuYWx5c2lzUm9vdCKKAWNocm9taXVtLm1lbW9yeS9MaW51eCBDaHJvbWl1bSBPUyBBU2FuIExTYW4gVGVzdHMgKDEpLzI3ODI2L2Jyb3dzZXJfdGVzdHMvU0c5emRHVmtRWEJ3VkdWemRDNVRhRzkxYkdSVGFHOTNURzlqWVhScGIyNUNZWEpFWVc1blpYSnZkWE12TVE9PQwLEhNNYXN0ZXJGbGFrZUFuYWx5c2lzGAIM


Automatically posted by the findit-for-me app (https://goo.gl/Ot9f7N).
Feedback is welcome! Please use component Tools>Test>FindIt>Flakiness

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/862c2db353e1f491f22ac932c6ab7d8378545eae

commit 862c2db353e1f491f22ac932c6ab7d8378545eae
Author: Alexandr Ilin <alexilin@chromium.org>
Date: Wed Jun 13 09:31:14 2018

Wait for url load in HostedAppTest.ShouldShowLocationBarDangerous

This CL fixes a race condition in the
HostedAppTest.ShouldShowLocationBarDangerous test. This test sets an app,
makes all further certificate validations to fail and then navigates inside the
app to the app url. The test expects that an interstitial page will be shown
after the navigation. Hovewer, there is a small probability that the nullptr
will be returned from WebContents::GetInterstitialPage().

The reason is that another navigation is triggered when the app is created and
the test doesn't wait for this navigation to complete before setting
cert_verifier to return an error. Two navigations trying to display an
interstitial page at the same time may make this test fail.

The fix is simple, we just have to wait for the first navigation to complete
before doing anything else.

Bug:  851232 
Change-Id: Ic3d55321efb23df726c8e178912704e15f3a54c8
Reviewed-on: https://chromium-review.googlesource.com/1097477
Reviewed-by: Giovanni Ortuño Urquidi <ortuno@chromium.org>
Commit-Queue: Alexandr Ilin <alexilin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#566773}
[modify] https://crrev.com/862c2db353e1f491f22ac932c6ab7d8378545eae/chrome/browser/ui/extensions/hosted_app_browsertest.cc