title: Custom UIButton layoutSubviews() doesn't work unless super.layoutSubviews() is called
body: <p>Code:</p>
  
  
  
  <pre><code>class ViewController: UIViewController{
  
      var button = CustomButton()
  
      override func viewDidLoad(){
          super.viewDidLoad()
          button.translatesAutoresizingMaskIntoConstraints = false
          view.addSubview(button)
          //add constraints and etc.
      }
  }
  
  class CustomButton: UIButton{
      override func layoutSubviews() {
          super.layoutSubviews()
          self.layer.cornerRadius = self.layer.frame.width * 0.5
          self.setTitle("abc", forState: .Normal)
      }
  }
  </code></pre>
  
  <p>Question 1: how come I have to call <code>super.layoutSubviews()</code> for the <code>setTitle()</code> to work? (i.e. the <code>cornerRadius</code> does get set but not the title)</p>
  
  <p>Question 2: I tried putting the code I have in <code>layoutSubviews()</code> in <code>drawRect()</code> but that doesn't change the <code>cornerRadius</code>.</p>