
Using "framebuffer_discard" in the list refers to an invalid extension. The extension which introduces glDiscardFramebufferEXT is "GL_EXT_discard_framebuffer". With this fix, cogl_gl_framebuffer_fbo_discard_buffers can actually call glDiscardFramebufferEXT. Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1974>