Add a swarming test trigger script for ChromeOS hardware tests.

It's a pretty lightweight script that simply adds the contents of the
//chromeos/CHROMEOS_LKGM file as a task dimension via the
"--optional-dimension" arg.

Bug: 866062
Change-Id: I550fc9abe1674a96bcd7d00f209c07e48c7dc252
Reviewed-on: https://chromium-review.googlesource.com/c/1405455
Reviewed-by: Stephen Martinis <martiniss@chromium.org>
Commit-Queue: Ben Pastene <bpastene@chromium.org>
Cr-Commit-Position: refs/heads/master@{#623073}
5 files changed