GitLab

This should fix 7 out of the top 10 flaky tests for Blink>Previews

The RunUntilIdle could potentially invoke a use after free if the UI
thread shuts down the http server but then this gets invoked since the
RunUntilIdle is actually called on the IO thread

Bug: 1004245
Change-Id: Ia749c8f0b412bab6fcf8008764f244b030f1f94b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1809554
Commit-Queue: Sophie Chang <sophiechang@chromium.org>
Reviewed-by: Tarun Bansal <tbansal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#697442}