title: Hiding Cancel button on search bar in UISearchController
body: <p>I'm trying to hide the Cancel button of the search bar in the UISearchController, but unfortunately setting the following in viewDidLoad() does not work:</p>
  
  <pre><code>override func viewDidLoad() {
      super.viewDidLoad()
  
      searchResultsTableController = UITableViewController()
      searchResultsTableController.tableView.delegate = self
  
      searchController = UISearchController(searchResultsController: searchResultsTableController)
      searchController.searchResultsUpdater = self
      searchController.searchBar.sizeToFit()
      searchResultsView.tableHeaderView = searchController.searchBar
  
      searchController.delegate = self
      searchController.dimsBackgroundDuringPresentation = false
      searchController.searchBar.delegate = self
  
      searchController.searchBar.searchBarStyle = .Minimal
      searchController.searchBar.showsCancelButton = false
  
      definesPresentationContext = true
  }
  </code></pre>
  
  <p>I have also tried using the above code in this delegate method:</p>
  
  <pre><code>func didPresentSearchController(searchController: UISearchController) {
      searchController.searchBar.showsCancelButton = false
  }
  </code></pre>
  
  <p>This approach works but will show the Cancel button briefly before hiding it, which is not ideal. Any suggestions?</p>