Ensure sub PopOverView doesn't run off end of ScrollView.
Ensure sub PopOverView doesn't run off end of ScrollView.

Fix the situation where a sub-PopOverView is inside a ScrollView which only
scrolls vertically and the initially calculated position for the PopOverView
runs off the side.

linagora/overture,Hokua/overture,adityab/overture,linagora/overture,fastmail/overture