Comment 11 for bug 1520537

I copied “mir_egl_mesa_display_is_valid” from _mir_display_is_valid in Mesa.

I should point out - we don't actually create any onscreen surfaces in Oxide. Everything we do is offscreen. We require pbuffer surfaces when we can't create surfaceless contexts.

Due to a breaking change in Chromium, I had to refactor this code so I took the opportunity to hopefully fix this at the same time (some of this is based on the existing logic in Chromium): http://bazaar.launchpad.net/~oxide-developers/oxide/crmaster/revision/1111