perfcheck instrument existing test : replaceAll

Change-Id: I7766aa6d69810124b27763912c3e7a8399637280
Reviewed-on: https://gerrit.libreoffice.org/12243
Reviewed-by: Matúš Kukan <matus.kukan@collabora.com>
Tested-by: Matúš Kukan <matus.kukan@collabora.com>