immediate disconnect in WebPlayer

I'm able to connect to a websocket server with this plugin. Inside the OnOpen callback, I send a message, and it's received by the server. ,

• If running in the webplayer, the socket disconnects immediately thereafter!
• In the editor, the websocket persists (as it should).

Here's a minimal test-case:

using System;
using UnityEngine;
using System.Collections;
using WebSocketSharp;
using WebSocketSharp.Net;

public class wstest : MonoBehaviour {

  string address  = "ws://192.168.1.223:9000/";
  WebSocket webSocket;

  void Start () {
    Debug.Log("starting " + address);
    Security.PrefetchSocketPolicy("192.168.1.223", 843, 3000);

    webSocket = new WebSocket(address);
    webSocket.OnOpen += OnOpen;
    webSocket.OnMessage += OnMessageReceived;
    webSocket.OnClose += OnClose;
    webSocket.OnError += OnError;
    webSocket.Connect();
  }

  // Update is called once per frame
  void Update () {
  }

  void OnOpen(object sender, System.EventArgs e) {
    webSocket.Send("hello");
  }

  void OnMessageReceived(object sender, MessageEventArgs e)
  {
  }

  void OnClose(object sender, CloseEventArgs e)
  {
  }

  void OnError(object sender, ErrorEventArgs e)
  {
  }
}

Start with the minimal Unity test case in the issue and compare the WebPlayer and editor connection lifecycles around OnOpen and Send. Reproduce the immediate disconnect, inspect the WebSocket connection and callback behavior used by the sample, and verify that the socket remains connected in WebPlayer after the message is sent.