widget: Fix disappearing mouse pointer

https://bugzilla.gnome.org/show_bug.cgi?id=725342
widget: Immediately resize the ring on app-initiated window resize

https://bugzilla.gnome.org/show_bug.cgi?id=647466
(cherry picked from commit 4425ee077bbedb1337e2e7d332e1137e68fd4adf)