     var libraryDrawerViewController: DrawerViewController?
     var webViewContainer: UIView!
     var urlBar: URLBarView!
+    var urlBarHeightConstraint: Constraint!
     var clipboardBarDisplayHandler: ClipboardBarDisplayHandler?
     var readerModeBar: ReaderModeBarView?
     var readerModeCache: ReaderModeCache

        statusBarOverlay.snp.remakeConstraints { make in
            make.top.left.right.equalTo(self.view)
            make.height.equalTo(self.view.safeAreaInsets.top)
        }
    }



        urlBar.snp.makeConstraints { make in
            make.leading.trailing.bottom.equalTo(urlBarTopTabsContainer)
            self.urlBarHeightConstraint = make.height.equalTo(UIConstants.TopToolbarHeightMax).constraint
            make.top.equalTo(topTabsContainer.snp.bottom)
        }

