Marked as blocked on 774301.

The issue will go away once we deploy Mac10.13 trybots. Or, we can hack webkitpy to add a special case.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/446adea8688f3a89836a7eb6b807f87fd5053d46

commit 446adea8688f3a89836a7eb6b807f87fd5053d46
Author: Robert Ma <robertma@chromium.org>
Date: Wed Jan 10 00:51:04 2018

Remove all lingering Mac10.13 test expectations

We don't have Mac10.13 try/CQ bots yet. These test expectations are
caused by  issue 800557 ; the example scenario described in that issue
happened during automatic rebaseline done by wpt-import.

Bug:  800557 
Change-Id: If27136d573dda56cb7323c8c8315c6c88019f9fa
Reviewed-on: https://chromium-review.googlesource.com/857698
Reviewed-by: Quinten Yearsley <qyearsley@chromium.org>
Commit-Queue: Robert Ma <robertma@chromium.org>
Cr-Commit-Position: refs/heads/master@{#528190}
[modify] https://crrev.com/446adea8688f3a89836a7eb6b807f87fd5053d46/third_party/WebKit/LayoutTests/TestExpectations

Is this still a valid issue? 

I think so -- last week skobes tried to fix this by marking the mac10.13 try bot as a rebaselining try bot, but this was reverted (https://chromium-review.googlesource.com/c/chromium/src/+/923781).

Hi Sarah, Dirk and Sergey,
With the migration of the Mac CQ to 10.13, are there now enough trybots on 10.13 as well?
Thanks,

The bug to track for the upgrade is issue 805475.

At the moment, we have 245 Mac10.13 bots: https://chromium-swarm.appspot.com/botlist?c=id&c=os&c=task&c=status&f=os%3AMac-10.13&l=100&s=id%3Aasc
and 195 Mac10.9 bots (to be upgraded): https://chromium-swarm.appspot.com/botlist?c=id&c=os&c=task&c=status&f=os%3AMac-10.9&l=100&s=id%3Aasc

I'm not sure what capacity requirements are needed for this issue, though 10.13 pool seems to be only lightly used at the moment: https://viceroy.corp.google.com/chrome_infra/Jobs/pools?duration=3w&pool=.%2Aos%3AMac-10.13.%2A&refresh=-1&service_name=chromium-swarm&utc_end=1519241721.56

which obviously will change once we switch more tasks from 10.9: https://viceroy.corp.google.com/chrome_infra/Jobs/pools?duration=3w&pool=.%2Aos%3AMac-10.9.%2A&refresh=-1&service_name=chromium-swarm&utc_end=1519241718.53

This is in fact the same as  issue 812784 , which has just been fixed. Duping this to that one as the other issue has more interesting commit history.

As for the capacity issue/concern, please track it in another issue.