Remove unnecessary code

lib/src/replaced_element.dart

@@ -120,7 +120,7 @@ class IframeContentElement extends ReplacedElement {
             : JavascriptMode.disabled,
         navigationDelegate: navigationDelegate,
         gestureRecognizers: {
-          Factory(() => PlatformViewVerticalGestureRecognizer())
+          Factory<VerticalDragGestureRecognizer>(() => VerticalDragGestureRecognizer()),
         },
       ),
     );
@@ -372,42 +372,3 @@ ReplacedElement parseReplacedElement(
       return EmptyContentElement(name: element.localName);
   }
 }
-
-// TODO(Sub6Resources): Remove when https://github.com/flutter/flutter/issues/36304 is resolved
-class PlatformViewVerticalGestureRecognizer
-    extends VerticalDragGestureRecognizer {
-  PlatformViewVerticalGestureRecognizer({PointerDeviceKind kind})
-      : super(kind: kind);
-
-  Offset _dragDistance = Offset.zero;
-
-  @override
-  void addPointer(PointerEvent event) {
-    startTrackingPointer(event.pointer);
-  }
-
-  @override
-  void handleEvent(PointerEvent event) {
-    _dragDistance = _dragDistance + event.delta;
-    if (event is PointerMoveEvent) {
-      final double dy = _dragDistance.dy.abs();
-      final double dx = _dragDistance.dx.abs();
-
-      if (dy > dx && dy > kTouchSlop) {
-        // vertical drag - accept
-        resolve(GestureDisposition.accepted);
-        _dragDistance = Offset.zero;
-      } else if (dx > kTouchSlop && dx > dy) {
-        // horizontal drag - stop tracking
-        stopTrackingPointer(event.pointer);
-        _dragDistance = Offset.zero;
-      }
-    }
-  }
-
-  @override
-  String get debugDescription => 'horizontal drag (platform view)';
-
-  @override
-  void didStopTrackingLastPointer(int pointer) {}
-}