Findit identified the culprit r570003 with confidence 70.0% in the config "chromium.win / Win7 Tests (dbg)(1)"
based on the flakiness trend:

https://findit-for-me.appspot.com/waterfall/flake?key=ag9zfmZpbmRpdC1mb3ItbWVyswELEhdNYXN0ZXJGbGFrZUFuYWx5c2lzUm9vdCJ9Y2hyb21pdW0ud2luL1dpbjcgVGVzdHMgKGRiZykoMSkvNjk5NDgvaGVhZGxlc3NfYnJvd3NlcnRlc3RzL1ZHRnlaMlYwUkc5dFlXbHVRM0psWVhSbFFXNWtSR1ZzWlhSbFVHRm5aVlJsYzNRdVVuVnVRWE41Ym1OVVpYTjAMCxITTWFzdGVyRmxha2VBbmFseXNpcxgBDA

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%20TargetDomainCreateAndDeletePageTest.RunAsyncTest&comment=Link%20to%20Analysis%3A%20https://findit-for-me.appspot.com/waterfall/flake?key=ag9zfmZpbmRpdC1mb3ItbWVyswELEhdNYXN0ZXJGbGFrZUFuYWx5c2lzUm9vdCJ9Y2hyb21pdW0ud2luL1dpbjcgVGVzdHMgKGRiZykoMSkvNjk5NDgvaGVhZGxlc3NfYnJvd3NlcnRlc3RzL1ZHRnlaMlYwUkc5dFlXbHVRM0psWVhSbFFXNWtSR1ZzWlhSbFVHRm5aVlJsYzNRdVVuVnVRWE41Ym1OVVpYTjAMCxITTWFzdGVyRmxha2VBbmFseXNpcxgBDA

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

This is a use-after-free. HeadlessContentMainDelegate::RunProcess frees the HeadlessBrowserImplForTest, which destroys the net::NetLog instance in HeadlessBrowserImpl. Meanwhile, URLRequestJob::NotifyDone is run on the IO thread and tries to add to the absent NetLog.

Assigning to skyostil@, who added HeadlessContentMainDelegate.
CC jam@ who added the NetLog to the HBI.

See https://chromium-swarm.appspot.com/task?id=3e55cb4477d24e10&refresh=10&show_raw=1 for nice logs.

See also https://test-results.appspot.com/dashboards/flakiness_dashboard.html#testType=headless_browsertests&tests=TargetDomainCreateAndDeletePageTest.RunAsyncTest

Removing Sheriff-Chromium and disabling the test.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/4337fd48039ae9958ebcabcefa514f6a5b1dca4b

commit 4337fd48039ae9958ebcabcefa514f6a5b1dca4b
Author: Greg Thompson <grt@chromium.org>
Date: Wed Jun 27 11:42:59 2018

Disable TargetDomainCreateAndDeletePageTest due to flakes.

BUG= 856720 
TBR=skyostil@chromium.org

Change-Id: If7de573f6c64d4f04ff08e1a82793fc3fc021ed7
Reviewed-on: https://chromium-review.googlesource.com/1116786
Reviewed-by: Greg Thompson <grt@chromium.org>
Commit-Queue: Greg Thompson <grt@chromium.org>
Cr-Commit-Position: refs/heads/master@{#570731}
[modify] https://crrev.com/4337fd48039ae9958ebcabcefa514f6a5b1dca4b/headless/lib/headless_devtools_client_browsertest.cc

+caseq@ who now owns headless.

FYI: this same UAF is happening in many tests. Fixing this will have a nice impact on test deflakage.

https://test-results.appspot.com/dashboards/flakiness_dashboard.html#testType=headless_browsertests&builder=chromium.memory%3ALinux%20MSan%20Tests

Closing this as this particular test has been removed, majority of tests has been rewritten into JS, and the net/ is no longer used by headless directly.