look for classes containing protected methods where we can convert them
all to private

Change-Id: I4a448341943e0a613cde30501c4012da61dba713
Reviewed-on: https://gerrit.libreoffice.org/44588Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>
Tested-by: Noel Grandin <noel.grandin@collabora.co.uk>