Failing tests (based on the last 14 builds, from 9339 to 9352, inclusive):

* external/wpt/background-fetch/fetch.https.window.html [x4]
* external/wpt/css/css-typed-om/interfaces.html [x11]
* external/wpt/mediacapture-streams/idlharness.https.window.html [x5]
* external/wpt/notifications/idlharness.https.any.html [x3]
* external/wpt/push-api/idlharness.https.any.html [x2]
* external/wpt/speech-api/idlharness.window.html [x6] [ Issue 872731 ]
* http/tests/background_fetch/block-cors-preflights.https.html [x4]
* virtual/outofblink-cors/external/wpt/service-workers/service-worker/fetch-canvas-tainting-video-cache.https.html [x3]

So definitely some repeat failures (especially that css-typed-om one). I'll quickly investigate, and probably disable all of these since it's not clear when they started failing. (Failures were less common before that, but still the same tests were failing before this.)

Ah OK, some of these are crashes, others timeouts. Now looking into the test runs:

The idlharness ones are all timing out:

* external/wpt/css/css-typed-om/interfaces.html [TIMEOUT]
* external/wpt/mediacapture-streams/idlharness.https.window.html [TIMEOUT]
* external/wpt/notifications/idlharness.https.any.html [TIMEOUT]
* external/wpt/push-api/idlharness.https.any.html [TIMEOUT]
* external/wpt/speech-api/idlharness.window.html [TIMEOUT] [ Issue 872731 ]

The background fetch ones are crashing:

* external/wpt/background-fetch/fetch.https.window.html [CRASH]
* http/tests/background_fetch/block-cors-preflights.https.html [CRASH]

And lol what:

* virtual/outofblink-cors/external/wpt/service-workers/service-worker/fetch-canvas-tainting-video-cache.https.html [PASS; expected CRASH]

The idlharness timeouts are Issue 856601.

The background-fetch crashes are Issue 869818.

These already had plenty of disabled tests in MSANExpectations. Just need to add a few more :(

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/67c441d2c33570fc281cef35a61169ad41a1a76b

commit 67c441d2c33570fc281cef35a61169ad41a1a76b
Author: Matt Giuca <mgiuca@chromium.org>
Date: Fri Aug 10 05:42:52 2018

WebKit Layout Tests: Disable a lot of flaky tests on MSAN.

Adds a bunch of tests with high-probability flake due to timeout or
crash, to existing lists of very similar tests that were already
disabled.

Tbr: mgiuca@chromium.org
Bug:  873045 ,  838057 , 856601, 869818
Change-Id: I66e14994ef4551d5690d3a66d51fce84a1eaf456
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/1170450
Reviewed-by: Matt Giuca <mgiuca@chromium.org>
Commit-Queue: Matt Giuca <mgiuca@chromium.org>
Cr-Commit-Position: refs/heads/master@{#582068}
[modify] https://crrev.com/67c441d2c33570fc281cef35a61169ad41a1a76b/third_party/WebKit/LayoutTests/MSANExpectations

The above tests have all been disabled. Follow-up on the 3 linked bugs.

The next build was green:
https://ci.chromium.org/buildbot/chromium.webkit/WebKit%20Linux%20Trusty%20MSAN/9355

There are more failing tests (new and old):
  external/wpt/picture-in-picture/idlharness.window.html
  external/wpt/WebCryptoAPI/idlharness.https.any.worker.html
  external/wpt/notifications/idlharness.https.any.worker.html
  external/wpt/xhr/idlharness.any.worker.html

in builds:
https://ci.chromium.org/buildbot/chromium.webkit/WebKit%20Linux%20Trusty%20MSAN/9464
https://ci.chromium.org/buildbot/chromium.webkit/WebKit%20Linux%20Trusty%20MSAN/9466
https://ci.chromium.org/buildbot/chromium.webkit/WebKit%20Linux%20Trusty%20MSAN/9471
https://ci.chromium.org/buildbot/chromium.webkit/WebKit%20Linux%20Trusty%20MSAN/9476
https://ci.chromium.org/buildbot/chromium.webkit/WebKit%20Linux%20Trusty%20MSAN/9477
https://ci.chromium.org/buildbot/chromium.webkit/WebKit%20Linux%20Trusty%20MSAN/9481
https://ci.chromium.org/buildbot/chromium.webkit/WebKit%20Linux%20Trusty%20MSAN/9482

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/7f46feee49916ee0a98a7092e495ceebbf135b96

commit 7f46feee49916ee0a98a7092e495ceebbf135b96
Author: Friedrich Horschig <fhorschig@chromium.org>
Date: Fri Aug 17 12:48:13 2018

[Flaky][Linux][MSAN] Mark more idlharness tests flaky

Marking some idlharness tests flaky as they have been the main point of
failure on a significant amount of Linux tests.

Tbr: mgiuca@chromium.org
Bug:  873045 
Change-Id: I798aeeadde74b34b458b8d05862dde5535a37d41
Reviewed-on: https://chromium-review.googlesource.com/1179750
Reviewed-by: Friedrich Horschig <fhorschig@chromium.org>
Commit-Queue: Friedrich Horschig <fhorschig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#584033}
[modify] https://crrev.com/7f46feee49916ee0a98a7092e495ceebbf135b96/third_party/WebKit/LayoutTests/MSANExpectations

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/529b158da2b374d372bdf69b42d06910585c19f4

commit 529b158da2b374d372bdf69b42d06910585c19f4
Author: Sahel Sharify <sahel@chromium.org>
Date: Thu Aug 23 20:53:55 2018

Update MSAN expectations for external/wpt/picture-in-picture/idlharness.window.html

Failure example:
https://ci.chromium.org/buildbot/chromium.webkit/WebKit%20Linux%20Trusty%20MSAN/9598

No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug:  873045 
Change-Id: I97f130469c20017f4fb4d336845bf89195729b1e
Reviewed-on: https://chromium-review.googlesource.com/1187126
Reviewed-by: Sahel Sharify <sahel@chromium.org>
Commit-Queue: Sahel Sharify <sahel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#585610}
[modify] https://crrev.com/529b158da2b374d372bdf69b42d06910585c19f4/third_party/WebKit/LayoutTests/MSANExpectations

Hasn't had any activity in awhile (this is sheriffing). Closing.