Merge "SystemClock: add test" am: 282e8fb037 am: a91a1a990f
am: 8f9a6372f6

* commit '8f9a6372f69f1528643cc24eab6048ab858b4997':
  SystemClock: add test

Change-Id: I4738ab2c9105099c92f5e583c9b5a2815dcc107e