Update lib/web_ui/test/engine/pointer_binding_test.dart

Author: Piinks

lib/web_ui/test/engine/pointer_binding_test.dart

@@ -1334,7 +1334,7 @@ void testMain() {
           packets[4].data[0].signalKind, equals(ui.PointerSignalKind.scroll));
       expect(
           packets[4].data[0].kind, equals(ui.PointerDeviceKind.trackpad));
-      expect(packets[4].data[0].pointerIdentifier, equals(-2));
+      expect(packets[4].data[0].device, equals(-2));
       expect(packets[4].data[0].pointerIdentifier, equals(0));
       expect(packets[4].data[0].synthesized, isFalse);
       expect(packets[4].data[0].physicalX, equals(10.0 * dpi));