Some GrabHelper uses are in the form:
doPreGrabStuff();
this._grabHelper.grab({
onUngrab: () => {
undoPreGrabStuff();
},
});
A promise-based variant allows to write this more cleanly as:
doPreGrabStuff();
await this._grabHelper.grabAsync();
undoPreGrabStuff();
https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/903
93fa1034f5