Function take_tick 

fn take_tick(
    damage: &RootDamage,
    conn: &RustConnection,
    trigger: TickTrigger,
) -> (bool, Option<Vec<Rectangle>>)

RootDamage::take for a tick trigger woke: whether the root changed since the last frame, and where. A report the take finds counts whatever woke the tick: one landing after the wait gave up is spent here all the same, and called clean, its change would be cleared with nothing left to report it (a capture that sends only changes would never send it).