Previously, I would cancel all the records associated with HistoryEntry that's
available for cancellation. This could cause unexpected behavior if we
cancelled a historyEntry which itself had cancelled records (in effect we would
negate the negation unintentionally). This is easily remedied by only
cancelling records which want to be cancelled.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=167204383