title: UIButton with CAShapeLayer makes title disappear while scrolling
body: <p>I have a <code>ProfileCollectionViewCell</code>with one method:</p>
  
  <pre><code>func configureCellWithProfile(profile: Profile) {
  
      shapeLayer.removeFromSuperlayer()
  
      let path = CGPathCreateMutable()
  
      CGPathMoveToPoint(path, nil, 0, 0)
      CGPathAddLineToPoint(path, nil, CGRectGetWidth(likeButton.frame), 0)
      CGPathAddLineToPoint(path, nil, CGRectGetWidth(likeButton.frame), CGRectGetHeight(likeButton.frame))
      CGPathCloseSubpath(path)
  
      shapeLayer.fillColor = profile.favourite ? UIColor.brilliantRose().CGColor : UIColor.blackSqueeze().CGColor
      shapeLayer.path = path
  
      likeButton.layer.masksToBounds = true
      likeButton.layer.addSublayer(shapeLayer)
  }
  </code></pre>
  
  <p>And just after load it looks like this:</p>
  
  <p><a href="https://i.stack.imgur.com/BX84cl.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/BX84cl.jpg" alt="enter image description here"></a></p>
  
  <p>but after I scroll my title (heart from icomoon font) disappear:</p>
  
  <p><a href="https://i.stack.imgur.com/HHajJl.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/HHajJl.jpg" alt="enter image description here"></a></p>
  
  <p><strong>Why?</strong></p>