
In future commits, we will want to create DMA-BUFs with pixel formats other than COGL_PIXEL_FORMAT_BGRX_8888. In preparation for that, let's start passing a new pixel format parameter to this function, and the corresponding winsys vfunc. All callers of this function pass COGL_PIXEL_FORMAT_BGRX_8888 for now. Next commits will change that. Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3175>