lkgm_manager_unittest: convert mox to mock

BUG=chromium:430770
TEST=`./cbuildbot/run_tests` passes

Change-Id: Iedff5651cd791f90d5e43c13f0842a28b56a9cec
Reviewed-on: https://chromium-review.googlesource.com/265356
Trybot-Ready: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Don Garrett <dgarrett@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
1 file changed