Add probe results to event log.

BUG=None
TEST=Manual

Change-Id: Ie58b16e0c89e402e4d6244bfd0e38e83d02f86fc
Reviewed-on: https://gerrit.chromium.org/gerrit/24287
Commit-Ready: Jon Salz <jsalz@chromium.org>
Reviewed-by: Jon Salz <jsalz@chromium.org>
Tested-by: Jon Salz <jsalz@chromium.org>