Findit identified the culprit r561582 with confidence 70.0% in the config "chromium.win / Win10 Tests x64"
based on the flakiness trend:

https://findit-for-me.appspot.com/waterfall/flake?key=ag9zfmZpbmRpdC1mb3ItbWVy4wELEhdNYXN0ZXJGbGFrZUFuYWx5c2lzUm9vdCKsAWNocm9taXVtLndpbi9XaW4xMCBUZXN0cyB4NjQvMjM4OTYvdml6X2NvbnRlbnRfYnJvd3NlcnRlc3RzIG9uIFdpbmRvd3MtMTAtMTUwNjMvVjJWaVVuUmpSMlYwVlhObGNrMWxaR2xoUW5KdmQzTmxjbFJsYzNRdVZIZHZSMlYwVlhObGNrMWxaR2xoVjJsMGFFVnhkV0ZzUTI5dWMzUnlZV2x1ZEhNdk1BPT0MCxITTWFzdGVyRmxha2VBbmFseXNpcxgBDA


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Feedback is welcome! Please use component Tools>Test>FindIt>Flakiness

Whackamole time.. see Issue 843844

r561582 is a Fuchsia roll - likely unrelated

But  Issue 846984  fingered a Viz change (albeit a revert - r560829 ). Which might be behind all these bugs.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/577963aecb20afb7be442fe782d9508b0a9b075e

commit 577963aecb20afb7be442fe782d9508b0a9b075e
Author: Trent Apted <tapted@chromium.org>
Date: Mon May 28 02:33:48 2018

Widen/disable some WebRtcGetUserMediaBrowserTest tests for flakiness

Affected:
 WebRtcGetUserMediaBrowserTest.SrcObjectRemoveFirstOfTwoVideoTracks
 WebRtcGetUserMediaBrowserTest.TwoGetUserMediaWithEqualConstraints
 WebRtcGetUserMediaBrowserTest.TwoGetUserMediaWithFirstHdSecondVga
 WebRtcGetUserMediaBrowserTest.TwoGetUserMediaAndCheckCallbackAfterFailure

It's flaky on more than just asan.

TBR=guidou@chromium.org

Bug: 843844,  847055 ,  846741 ,  846984 ,  846960 
Change-Id: I6edb91ee741a5e57a950f98e23926f5b96515a01
Reviewed-on: https://chromium-review.googlesource.com/1074774
Commit-Queue: Trent Apted <tapted@chromium.org>
Reviewed-by: Trent Apted <tapted@chromium.org>
Cr-Commit-Position: refs/heads/master@{#562165}
[modify] https://crrev.com/577963aecb20afb7be442fe782d9508b0a9b075e/content/browser/webrtc/webrtc_getusermedia_browsertest.cc