Comment 4 for bug 1520537

This is failing to find an EGL config using the attributes provided by Chromium, which are:

EGL_BUFFER_SIZE, 32,
EGL_ALPHA_SIZE, 8,
EGL_BLUE_SIZE, 8,
EGL_GREEN_SIZE, 8,
EGL_RED_SIZE, 8,
EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
EGL_SURFACE_TYPE, EGL_WINDOW_BIT,
EGL_NONE

We already do a runtime check for Mir/Mesa to strip EGL_PBUFFER_BIT from the attributes supplied by Chromium.

This used to work, but doesn't anymore.