Add performance monitoring script during update.

The autoupdate_EndToEndTest has a script that it uses to measure the
peak memory used during an update. The test now uses the
devserver-on-dut provision flow and we temporarily removed
the performance monitoring flow. This adds it back

The test will copy the the script to the DUT during its setup.
chromite/lib/auto_updater will then kick off the script during rootfs
update and save the results to a file.

This can be submitted before or after the autotest CL.

BUG=chromium:709710
TEST=cros flash still works
TEST=autoupdate_EndToEnd with this change

Change-Id: I0cccede985d0bdce2d9525939b37ffc61c690c30
Reviewed-on: https://chromium-review.googlesource.com/564324
Commit-Ready: David Haddock <dhaddock@chromium.org>
Tested-by: David Haddock <dhaddock@chromium.org>
Reviewed-by: Xixuan Wu <xixuan@chromium.org>
1 file changed