title: Set content offset of presented view controller's scroll view before it's presented?
body: <p>I have a container <code>scrollView</code> that contains a regular collection view and collection view cells inside of it (There are a couple custom views inside of it that aren't collection view cells, hence why I have a container scroll view and not just a collection view).</p>
  
  <p>When a user taps a cell, I instantiate and present a view controller programmatically:</p>
  
  <pre><code>let storyboard = UIStoryboard(name: "Main", bundle: nil)
  let secondVC = storyboard.instantiateViewControllerWithIdentifier("second") as! SecondViewController
  self.presentViewController(secondVC, animated: false, completion: nil)
  </code></pre>
  
  <p>That works great. Now, I want to transition back to the original view controller at a certain content offset. So I have a method in my second view controller to perform this transition back:</p>
  
  <pre><code>let storyboard = UIStoryboard(name: "Main", bundle: nil)
  let firstVC = storyboard.instantiateViewControllerWithIdentifier("first") as! FirstViewController
  // There's an IBOutlet for my containerScrollView
  firstVC.containerScrollView.setContentOffset(CGPoint(x: 500, y: 0), animated: false)
  self.presentViewController(firstVC, animated: false, completion: nil)
  </code></pre>
  
  <p>The transition back to <code>firstVC</code> performs fine, but it always starts at the beginning of the container scroll view in <code>firstVC</code> rather than what I set for the custom content offset. I've checked to make sure that the <code>containerScrollView</code> property on the <code>firstVC</code> exists before I try setting the content offset, and it does exist. Is there a way to do this?</p>