Steps to Reproduce

Create a custom context menu in Flutter. Flutter Web still shows the default browser context menu while Flutter Desktop shows a custom context menu.

Use case:
In Dart DevTools I would like to show some custom actions as part of the right click menu to navigate to other portions of Dart DevTools.

When Dart DevTools is run in chrome, I just see the built in context menu.

https://www.jquery-az.com/jquery/demo.php?ex=121.0_2
shows an example of a jquery library that likely uses preventDefault() to enable custom right click context menus.

#78671 is a related issue to suppress the browser default right click context menu but not supportcustom right click menus.