Remove AsyncTestCase usage from perf/ folder. ------------- Created by MOE: https://github.com/google/moe MOE_MIGRATED_REVID=121286819
Remove AsyncTestCase usage from perf/ folder.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=121286819

google/lovefield,google/lovefield,google/lovefield