GitLab

Cause of flake was confirmed by adding a slow unload handler to |popup|. This
fixes it.

Bug: 821596, 822635
Change-Id: I602c98a0fb37f9951cc85fb9d886616bb22e8b42
Reviewed-on: https://chromium-review.googlesource.com/967352Reviewed-by: Reilly Grant <reillyg@chromium.org>
Commit-Queue: Nick Carter <nick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#543870}