title: WebApi: how to pass state from filter to controller?
body: <p>I am pulling some user data in action filter, and could use some of that data in a controller's action, but not exactly sure how to pass data from a filter to a controller.
  In MVC I'd probably use session or HttpContext.Items, but it's not available in web api. Another option is to use ThreadStatic, but I think there has to be a better solution?</p>