Findit identified the culprit r556170 with confidence 70.0% in the config "chromium.memory / Mac ASan 64 Tests (1)"
based on the flakiness trend:

https://findit-for-me.appspot.com/waterfall/flake?key=ag9zfmZpbmRpdC1mb3ItbWVy2QELEhdNYXN0ZXJGbGFrZUFuYWx5c2lzUm9vdCKiAWNocm9taXVtLm1lbW9yeS9NYWMgQVNhbiA2NCBUZXN0cyAoMSkvNDA0ODUvYnJvd3Nlcl90ZXN0cy9VSEpsYzJWdWRHRjBhVzl1VW1WalpXbDJaWEpYYVc1a2IzZERiMjUwY205c2JHVnlRbkp2ZDNObGNsUmxjM1F1VUhKbGMyVnVkR0YwYVc5dVFYQnBRMjl0YlhWdWFXTmhkR2x2Ymc9PQwLEhNNYXN0ZXJGbGFrZUFuYWx5c2lzGAEM


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

r556170 is a Fuchsia-only change, so it cannot be the culprit.

Closing as WontFix since the test has not failed in the last few runs.
A new bug will be filed if the test continues to flake.

Adjustments are being made to Findit's confidence score and lookback algorithm to reduce false positives like this one in https://chromium-review.googlesource.com/c/infra/infra/+/1069832

Setting to available to be assigned the proper component/owner to fix or disable this flaky test, removing Findit>Flakiness from components

btolsch@: please fix or disable the test and remove Sheriff-Chromium. You can wait for a sheriff to disable the test for you, but that's not as nice :)

https://chromium-try-flakes.appspot.com/all_flake_occurrences?key=ahVzfmNocm9taXVtLXRyeS1mbGFrZXNyVwsSBUZsYWtlIkxQcmVzZW50YXRpb25SZWNlaXZlcldpbmRvd0NvbnRyb2xsZXJCcm93c2VyVGVzdC5QcmVzZW50YXRpb25BcGlDb21tdW5pY2F0aW9uDA

has

try run at 2018-05-21 17:08:00 UTC	(milo)	patchset	linux_chromium_rel_ng	
try run at 2018-05-18 18:43:45 UTC	(milo)	patchset	linux_chromium_rel_ng	
 
try run at 2018-05-02 01:47:41 UTC	(milo)	patchset	mac_chromium_rel_ng	
 
try run at 2018-04-27 02:08:28 UTC	(milo)	patchset	linux_chromium_rel_ng	
try run at 2018-04-25 16:00:51 UTC	(milo)	patchset	linux-chromeos-rel	
try run at 2018-04-24 23:01:40 UTC	(milo)	patchset	mac_chromium_rel_ng	
try run at 2018-04-23 19:19:35 UTC	(milo)	patchset	linux_chromium_rel_ng


That's a fair number of flakes. Two come after #c4, so I think this is still flaky.

I believe I'm able to repro this with a lot of repetition.  If I can't make any debugging progress soon I'll disable it.

I checked https://chromium-review.googlesource.com/dashboard/btolsch@chromium.org in case you had a WIP

disabling to remove from sheriff queue

CL -> https://chromium-review.googlesource.com/#/c/chromium/src/+/1074800 

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/5ae5d7872b2c15386c971579163a7e3d22695a33

commit 5ae5d7872b2c15386c971579163a7e3d22695a33
Author: Trent Apted <tapted@chromium.org>
Date: Mon May 28 03:21:50 2018

Disable flaky PresentationReceiverWindowControllerBrowserTest.PresentationApiCommunication

TBR=btolsch@chromium.org

Bug: 840136
Change-Id: I056bb43c5ce15844107951fbc09cf1772e514828
Reviewed-on: https://chromium-review.googlesource.com/1074800
Reviewed-by: Trent Apted <tapted@chromium.org>
Commit-Queue: Trent Apted <tapted@chromium.org>
Cr-Commit-Position: refs/heads/master@{#562175}
[modify] https://crrev.com/5ae5d7872b2c15386c971579163a7e3d22695a33/chrome/browser/ui/media_router/presentation_receiver_window_controller_browsertest.cc