How to hide the toolbar when web view is swiped without a navigation controller?

Can't seem to find the answer. I have a webView with a toolbar at the bottom. hidesBarsOnSwipe only works if you have a navigation controller, which I am not using. toolBar.isHidden = true hides it but how do I unhide when user swipes up? Thank You so much for any help. Still learning swift :) OH! I am using Xcode 8 Swift 3