Add user to active sessions reporting.

Previously, active sessions and recent users were reported separately,
that is confusing on the server side.
This change adds 'user_email' field to ActiveTimePeriod proto message
and populates it for affiliated users that are eligible for reporting.
Also, user email is reported only if user reporting is turned on.

BUG=810093
TEST=Browser tests added.

Change-Id: I92fec6725349972895ec0a439f78efa59853670e
Reviewed-on: https://chromium-review.googlesource.com/904527
Reviewed-by: Maksim Ivanov <emaxx@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Sergey Poromov <poromov@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#537435}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: d9b74d0c8c1e8686ffd0bb06cf16c7fcc89bdf66
1 file changed