Findit identified the culprit r575462 with confidence 70.0% in the config "chromium.memory / Linux ChromiumOS MSan Tests"
based on the flakiness trend:

https://findit-for-me.appspot.com/waterfall/flake?key=ag9zfmZpbmRpdC1mb3ItbWVysQELEhdNYXN0ZXJGbGFrZUFuYWx5c2lzUm9vdCJ7Y2hyb21pdW0ubWVtb3J5L0xpbnV4IENocm9taXVtT1MgTVNhbiBUZXN0cy83OTU2L2FzaF91bml0dGVzdHMvVjJsdVpHOTNVMlZzWldOMGIzSlVaWE4wTGxKdmRXNWtaV1JGWkdkbFRXRnphMVpwYzJsaWFXeHBkSGs9DAsSE01hc3RlckZsYWtlQW5hbHlzaXMYAQw

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%20WindowSelectorTest.RoundedEdgeMaskVisibility&comment=Link%20to%20Analysis%3A%20https://findit-for-me.appspot.com/waterfall/flake?key=ag9zfmZpbmRpdC1mb3ItbWVysQELEhdNYXN0ZXJGbGFrZUFuYWx5c2lzUm9vdCJ7Y2hyb21pdW0ubWVtb3J5L0xpbnV4IENocm9taXVtT1MgTVNhbiBUZXN0cy83OTU2L2FzaF91bml0dGVzdHMvVjJsdVpHOTNVMlZzWldOMGIzSlVaWE4wTGxKdmRXNWtaV1JGWkdkbFRXRnphMVpwYzJsaWFXeHBkSGs9DAsSE01hc3RlckZsYWtlQW5hbHlzaXMYAQw

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

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/fed7475d501d0622e3604313eb93867405cba55f

commit fed7475d501d0622e3604313eb93867405cba55f
Author: Owen Min <zmin@chromium.org>
Date: Tue Jul 17 17:45:11 2018

Disable two flaky tests on ChromeOS

Disable ShelfLayoutManagerTest.FlingUpOnShelfForFullscreenAppList
Disable WindowSelectorTest.RoundedEdgeMaskVisibility

Tbr: xiyuan, xdai
Bug:  864467 ,  864465 
Change-Id: I77a0dbcddad5176575f0dc5991beb9eef8090167
Reviewed-on: https://chromium-review.googlesource.com/1140683
Reviewed-by: Owen Min <zmin@chromium.org>
Commit-Queue: Owen Min <zmin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#575707}
[modify] https://crrev.com/fed7475d501d0622e3604313eb93867405cba55f/ash/shelf/shelf_layout_manager_unittest.cc
[modify] https://crrev.com/fed7475d501d0622e3604313eb93867405cba55f/ash/wm/overview/window_selector_unittest.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/07f7e41c511c5ebc86d5606614da07ff37f41d07

commit 07f7e41c511c5ebc86d5606614da07ff37f41d07
Author: CJ DiMeglio <lethalantidote@chromium.org>
Date: Wed Jul 18 00:12:18 2018

Revert "Disable two flaky tests on ChromeOS"

This reverts commit fed7475d501d0622e3604313eb93867405cba55f.

Reason for revert: <INSERT REASONING HERE>

Original change's description:
> Disable two flaky tests on ChromeOS
> 
> Disable ShelfLayoutManagerTest.FlingUpOnShelfForFullscreenAppList
> Disable WindowSelectorTest.RoundedEdgeMaskVisibility
> 
> Tbr: xiyuan, xdai
> Bug:  864467 ,  864465 
> Change-Id: I77a0dbcddad5176575f0dc5991beb9eef8090167
> Reviewed-on: https://chromium-review.googlesource.com/1140683
> Reviewed-by: Owen Min <zmin@chromium.org>
> Commit-Queue: Owen Min <zmin@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#575707}

TBR=zmin@chromium.org

Change-Id: I2aaceb5588030a1b14edf9b0c1d2da6165cbf8f1
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug:  864467 ,  864465 
Reviewed-on: https://chromium-review.googlesource.com/1140460
Reviewed-by: CJ DiMeglio <lethalantidote@chromium.org>
Commit-Queue: CJ DiMeglio <lethalantidote@chromium.org>
Cr-Commit-Position: refs/heads/master@{#575865}
[modify] https://crrev.com/07f7e41c511c5ebc86d5606614da07ff37f41d07/ash/shelf/shelf_layout_manager_unittest.cc
[modify] https://crrev.com/07f7e41c511c5ebc86d5606614da07ff37f41d07/ash/wm/overview/window_selector_unittest.cc

(Reason for the revert is that we believe we fixed the root cause of this in cr/864358)