Update counters in data stream sender for broadcast.

Change-Id: I2e42bc2aaf48cfd819a161cad1acf7df1684cf07
Reviewed-on: http://gerrit.sjc.cloudera.com:8080/4174
Reviewed-by: Alex Behm <alex.behm@cloudera.com>
Reviewed-by: Nong Li <nong@cloudera.com>
Tested-by: Nong Li <nong@cloudera.com>