GitLab

Also add a test double for BackgroundEidGenerator.

Bug: 819279
Change-Id: I24e2352d72deb00632a4d955f17cc508f7d4cbb5
Reviewed-on: https://chromium-review.googlesource.com/952462Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Commit-Queue: Ryan Hansberry <hansberry@chromium.org>
Cr-Commit-Position: refs/heads/master@{#545117}