78d6b13c29
Updating scroll position may have significant side effects, e.g. switching workspace; this should never happen during allocation, as we're in the middle of painting a frame. So, put it in an idle callback if we're doing it from an allocation to have the side effects happen the right time. Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1527>