Overscroll effect never goes away for mouse scrolling
At some point during the past cycle the overscroll gradient stopped going away after a timeout when scrolling with a mouse (though it works fine with touch/touchpad). According to @exalm the reason is that we added support for hold gestures so the timeout isn't needed there anymore, but since it was removed for everything, it's now broken for mice because there is no equivalent for that gesture there.
Can we reintroduce a timeout for input devices that don't have hold gestures (mainly mouse and trackpoint)?
Since this is a fairly visible issue it'd be nice to avoid shipping 43 with it.
cc @exalm @aday