[resource-timing] Preemptive TestExpectations for added flaky test

https://github.com/web-platform-tests/wpt/pull/13823 introduces a
test which is flaky in Chromium, due to a Chromium issue.
This CL will enable that test to be imported without flaking the bots.

Bug: 941482
Change-Id: I7568bd00d55743ab140f428b807cf2ffc92a9fda
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1520601
Commit-Queue: Robert Ma <robertma@chromium.org>
Reviewed-by: Robert Ma <robertma@chromium.org>
Cr-Commit-Position: refs/heads/master@{#640459}
1 file changed