Move off of internal SDK, copy webkit spis from opensource

App/Document Controls UI/DocumentControlItemView.swift

@@ -103,9 +103,16 @@ class DocumentControlItemView: UIControl
         separatorView.isHidden = !drawsBottomSeparator
     }
     
-    override func setTracking(_ tracking: Bool) {
-        super.setTracking(tracking)
-        highlightView.isHidden = !tracking
+    override func beginTracking(_ touch: UITouch, with event: UIEvent?) -> Bool {
+        super.beginTracking(touch, with: event)
+        highlightView.isHidden = false
+        
+        return true
+    }
+    
+    override func endTracking(_ touch: UITouch?, with event: UIEvent?) {
+        super.endTracking(touch, with: event)
+        highlightView.isHidden = true
     }
     
     public func title(_ title: String) -> Self {