Own binlog may need to be treated by a slave server as a replication source.
E.g to block own groups of events arrival in circular semisync setups.
That is when a incoming GTID exists in the slave's binlog it would be
silently ignored, rather that to emit Out-Of-Order error, similarly as if it had been received from another source to
the --gtid-ignore-duplicates configured slave.
To activate such policy --gtid-ignore-binlog-duplicates boolean option
The new option is deprecated at once for it to be merged with --gtid-ignore-duplicates
which will then become enum in next non-GA version.
The proposed method is more general than CHANGE_MASTER TO ... IGNORE_DOMAIN_IDS or
a legacy one based on the same server id.