crosperf: use sshwatcher to set up port forwarding to DUTs

Some DUTs (notably those on gTransit) require port forwarding to be
accessible from inside the chroot. This CL makes crosperf's SuitRunner
use sshwatcher to set up the required forwarding.

BUG=b:235119397
TEST=suite_runner_unittest, then try it out for real

Change-Id: Idad2abf40713e2d0aa3b81fdb4762a22b638400e
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/toolchain-utils/+/3928354
Reviewed-by: Denis Nikitin <denik@chromium.org>
Reviewed-by: Jordan Abrahams-Whitehead <ajordanr@google.com>
Commit-Queue: Bob Haarman <inglorion@chromium.org>
Tested-by: Bob Haarman <inglorion@chromium.org>
2 files changed