The certificate authority and server certificates here are generated by $topsrcdir/build/pgo/genpgocert.py.

You can generate a new CA cert by running:
$objdir/_virtualenv/bin/python $topsrcdir/build/pgo/genpgocert.py --gen-ca

You can generate new server certificates by running:
$objdir/_virtualenv/bin/python $topsrcdir/build/pgo/genpgocert.py --gen-server

These will place the new files in this directory where you can commit them.