Add probe results to event log.

BUG=None
TEST=Manual

Change-Id: Icb6a2047553ea2787443b587769b40f671d05c30
Reviewed-on: https://gerrit.chromium.org/gerrit/24288
Reviewed-by: Jon Salz <jsalz@chromium.org>
Tested-by: Jon Salz <jsalz@chromium.org>