GitLab

Serial number should be put at the top level of report as it doesn't belong
to any Browser or Profile instance.

Bug: 910594
Change-Id: I1a70c322814c3b7f03ac3d8bf23ea64c38e31d22
Reviewed-on: https://chromium-review.googlesource.com/c/1372713
Commit-Queue: Owen Min <zmin@chromium.org>
Reviewed-by: Julian Pastarmov <pastarmovj@chromium.org>
Cr-Commit-Position: refs/heads/master@{#615896}