XWayland defaults to a 1hz refresh rate when the surface is not
visible, but this can sometimes cause issues in Chrome. If we see
a bogus rate like that, ANGLE can just report 30hz.

Bug: chromium:1042393
Change-Id: I554b05b4107cea528525ced6e95a5ce529eec3b1
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2422084Reviewed-by: Jonah Ryan-Davis <jonahr@google.com>