title: Scrolling a UIScrollView changes its subviews frames
body: <p>My app uses storyboards and autolayout. In a view controller I created a <code>UIScrollView</code> and added three subviews. </p>
  
  <p>At run time I need to change  the sizes of the subviews and rearrange them. Initially, I rearrange them in <code>viewDidLayoutSubviews</code>, and it seems to work until I scroll the scroll view. Then the subview frames are changed back to the sizes that are set in IB. (I'm setting the <code>UIScrollView</code>'s content size when rearranging the views and removing all <code>UIViewConstraints</code>.)</p>