Summary:
After replaying the WALs, the memtables are flushed synchronously to L0 instead of being flushed in background. Currently, we only track WAL obsoletion events in the code path of background flush jobs. This PR tracks these events in RecoverLogFiles.
After this change, we can enable `track_and_verify_wal_in_manifest` in `db_stress`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7649
Test Plan: `python tools/db_crashtest.py whitebox`
Reviewed By: riversand963
Differential Revision: D24824501
Pulled By: cheng-chang
fbshipit-source-id: 207129f7b845c50b333680ce6818a68a2fad54b9