What does asp.net mvc 4.0 use for JSON serialization?

I am using asp.net mvc 4. Looking at some tutorials I have created my own JsonResult class inheriting from OOB JsonResult class to use Json.Net. Below is how my class looks.

public class JsonNetResult : JsonResult
{
    private readonly object _data;

    public JsonNetResult(object data)
    {
        if (data == null)
        {
            throw new ArgumentNullException("data");
        }

        _data = data;
    }

    public override void ExecuteResult(ControllerContext context)
    {
        if (context == null)
        {
            throw new ArgumentNullException("context");
        }

        var response = context.HttpContext.Response;
        response.ContentType = "application/json";
        var writer = new JsonTextWriter(response.Output);
        var serializer = JsonSerializer.Create(new JsonSerializerSettings());
        serializer.Serialize(writer, _data);
        writer.Flush();
    }
}

What I wanted to ask is

1. whether this class is required, or .net is using Json.Net internally for serializing the object.
2. Also can I directly bind a serialized model to the view.