Add power_DeferForFlashrom server test.

Add a test to verify that powerd defers suspending or
rebooting the system while flashrom is running.

BUG=chromium:400641
TEST=ran it against x86-generic
CQ-DEPEND=CL:217381
CQ-DEPEND=CL:217994

Change-Id: Ib966ee56401c7999bf82cc35c6e11d4df254db95
Reviewed-on: https://chromium-review.googlesource.com/218512
Reviewed-by: Daniel Erat <derat@chromium.org>
Tested-by: Daniel Erat <derat@chromium.org>
Reviewed-by: Derek Basehore <dbasehore@chromium.org>
Commit-Queue: Daniel Erat <derat@chromium.org>
2 files changed