Add flag to crosperf to use file lock mechanism.

This CL adds a flag to crosperf that specifies using the old file
locking mechanism, rather than the new AFE server locking mechanism.
This is useful when there are issues with accessing the AFE server.

BUG=None
TEST=Tested crosperf with this, both using the AFE locking mechanism
and using the file locking mechanism.

Change-Id: If6aa3e97a77d8ccb53f0e8f0405cc7f45e983b75
Reviewed-on: https://chrome-internal-review.googlesource.com/219096
Reviewed-by: Luis Lozano <llozano@chromium.org>
Commit-Queue: Caroline Tice <cmtice@google.com>
Tested-by: Caroline Tice <cmtice@google.com>
5 files changed