
Use the surfaceless platform in the headless backend to initialize the GL-renderer and create pbuffer outputs. This allows headless backend to use GL-renderer, even hardware accelerated. This paves way for exercising GL-renderer in CI and using the Weston test suite to test hardware GL ES implementations. Relates to: https://gitlab.freedesktop.org/wayland/weston/issues/278 Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>