 the controls. So we capture mouse events that bubble up to the
player and report activity when that happens.
With touch events it isn't as easy. We can't rely on touch events at the
player level, because a tap (touchstart + touchend) on the video itself on
mobile devices is meant to turn controls off (and on). User activity is
checked asynchronously, so what could happen is a tap event on the video
turns the controls off, then the touchend event bubbles up to the player,
which if it reported user activity,