Revert "Remove a misleading "flush" function."

This reverts commit 9d8b92685946c5029a71ac7d90b6b68dceecc773.

Reason for revert: Driodcop: aosp-master test-mapping showing multiple failures (b/140336855).

Change-Id: If44e273dd111802db8b44db1e5a67a4628c72e3c
5 files changed