Add timestamps to test results

This CL adds a timestamp to each gesture that appears in the report.
This can be useful for knowing when some anomolus event occured during a
test run (such as the network failing, power loss, etc) so you can
differentiate which tests occured before the issue and which happened
after/during.  Especially for the noise test where the order is
randomized, this can be useful information.

BUG=chromium:620090
TEST=manually tested, the reports look good and the timestamps appear to
be accurate

Change-Id: I9f4c6bb538b77d09e4b85fb0d0d50681c751a3d7
Signed-off-by: Charlie Mooney <charliemooney@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/352593
Reviewed-by: Shyh-In Hwang <josephsih@chromium.org>
3 files changed