tree 1c97dec93e5fb217756d533db0c21af273e17a1b
parent ef87018af89966824f881d158ca8883255bb018c
author David Blaikie <dblaikie@gmail.com> 1613510001 -0800
committer Copybara-Service <copybara-worker@google.com> 1613732206 -0800

Fix -Wnon-virtual-dtor by making the ctor protected

GitOrigin-RevId: f8af06d60d9c5bcf6104bf6540350fb0fb1d7ac5