48122e2c11
(This is a merge of http://go/wvgerrit/107243.) This code is based on a bug report and patch from Sony. The TimeRollbackPrevention test was failing when run with CE CDM and the OEC Ref, although it passed in some other configurations. The cause was twofold: 1) The test sleep code was not accounting for rollback when calculating the clock drift, causing incorrect time values to elapse. 2) Fixing the previous exposed a bug in the CE CDM test host where it did not handle negative time passing correctly. This patch expands Sony's fix with additional comments and some code cleanup to try to make the code clearer and more robust against future errors, particularly in the error-prone TestHost code. Bug: 169942369 Test: jenkins/ce_cdm_tests Test: build_and_run_all_unit_tests.sh Test: x86-64, all CE CDM unit tests Change-Id: Id52b8c38255f70b04bc2735c4e309fb90992f53e