update TxnSizeEstimate
update TxnSizeEstimate

Change-Id: Ifbe31b7e9d3bc2435564614ae534adc574015d4a
Reviewed-on: http://review.couchbase.org/c/perfrunner/+/139018
Tested-by: Build Bot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>
Reviewed-by: Korrigan Clark <11cf3ebdc6cba78053c91b2fd94cb21b47d0d02e@couchbase.com>

couchbase/perfrunner,couchbase/perfrunner,couchbase/perfrunner,couchbase/perfrunner,couchbase/perfrunner,couchbase/perfrunner