     fileprivate var topURLBarConstraints = [Constraint]()
     fileprivate let requestHandler = RequestHandler()
     fileprivate var findInPageBar: FindInPageBar?
+    fileprivate var fillerView: UIView?
     fileprivate let alertStackView = UIStackView() // All content that appears above the footer should be added to this view. (Find In Page/SnackBars)
 
     fileprivate var drawerConstraint: Constraint!

        let scrollView = webViewController.scrollView

        scrollBarState = .animating
        UIView.animate(withDuration: UIConstants.layout.urlBarTransitionAnimationDuration, delay: 0, options: .allowUserInteraction, animations: {
            self.urlBar.collapseUrlBar(expandAlpha: 1, collapseAlpha: 0)
            self.urlBarTopConstraint.update(offset: 0)

            if let keyboardHeight = keyboardState?.intersectionHeightForView(view: self.view), keyboardHeight > 0 {
                make.bottom.equalTo(self.view).offset(-keyboardHeight)
            } else if !browserToolbar.isHidden {
                // is an iPhone
                make.bottom.equalTo(self.browserToolbar.snp.top).priority(.low)
                make.bottom.lessThanOrEqualTo(self.view.safeAreaLayoutGuide.snp.bottom).priority(.required)
            } else {
                // is an iPad
                make.bottom.equalTo(self.view.safeAreaLayoutGuide.snp.bottom)
            }
        }
    }
