GNOME 44 Mutter Adds fractional_scale_v1 Wayland Support

While GNOME 3.32 saw initial work on fractional scaling support for the GNOME Shell and Mutter compositor, the upcoming GNOME 44 release is bringing support for Wayland's fractional_scale_v1 protocol.

The fractional_scale_v1 protocol is used for communicating preferred fractional scales to surfaces and with the wp_viewport protocol can be used to render surfaces at fractional scales. This new Wayland protocol for fractional scaling was merged to Wayland-Protocols last April.

This saw KDE Plasma supporting Wayland fractional scaling using the new protocol, Sway and wlroots supporting it too, and now ahead of this month's GNOME 44 release is fractional_scale_v1 support in Mutter.

This merge request had been open and in the works for ten months while was finally merged on Saturday evening. This joins other last-minute GNOME 44 work like Mutter experimental HDR modes and dropping the last GTK3 dependencies in Mutter and the GNOME Shell.