Cleanup scheduler unit test a bit.
Cleanup scheduler unit test a bit.

R=bmeurer@chromium.org
TEST=unittests/SchedulerTest,unittests/SchedulerRPOTest

Review URL: https://codereview.chromium.org/927653004

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#26778}

UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh