     private let urlBarBackgroundView = UIView()
     private var showButtons = false
 
-    private var fullWidthURLTextConstraint: Constraint!
-    private var centeredURLConstraint: Constraint!
+    private var fullWidthURLTextConstraints = [Constraint]()
+    private var centeredURLConstraints = [Constraint]()
     private var hideLockConstraints = [Constraint]()
     private var hideToolsetConstraints = [Constraint]()
     private var showToolsetConstraints = [Constraint]()
     private var isEditingConstraints = [Constraint]()
-    private var notEditingConstraints = [Constraint]()
     private var preActivationConstraints = [Constraint]()
     private var postActivationConstraints = [Constraint]()
 

            self.updateToolsetConstraints()

            if self.showButtons {
                self.notEditingConstraints.forEach { $0.deactivate() }
                self.isEditingConstraints.forEach { $0.activate() }
            }


            // If we're editing, stretch the text field to the full width of its container.
            // Otherwise it will size to fit, allowing it to be centered in the container.
            if isEditing {
                centeredURLConstraints.forEach { $0.deactivate() }
                fullWidthURLTextConstraints.forEach { $0.activate() }
            } else {
                fullWidthURLTextConstraints.forEach { $0.deactivate() }
                centeredURLConstraints.forEach { $0.activate() }
            }
        }
    }
