Fix web.PointerData

lib/web_ui/lib/pointer.dart

@@ -89,6 +89,7 @@ class PointerData {
     this.panDeltaY = 0.0,
     this.scale = 0.0,
     this.rotation = 0.0,
+    this.viewId = 0,
     this.preferredStylusAuxiliaryAction = PointerPreferredStylusAuxiliaryAction.ignore,
   });
   final int embedderId;
@@ -126,6 +127,7 @@ class PointerData {
   final double panDeltaY;
   final double scale;
   final double rotation;
+  final int viewId;
   final PointerPreferredStylusAuxiliaryAction preferredStylusAuxiliaryAction;
 
   @override
@@ -166,6 +168,7 @@ class PointerData {
            'panDeltaY: $panDeltaY, '
            'scale: $scale, '
            'rotation: $rotation, '
+           'viewId: $viewId, '
            'preferredStylusAuxiliaryAction: $preferredStylusAuxiliaryAction'
            ')';
   }