Using gree's unity-webview in EditorWindow

WebViewEditorWindow.cs

# Using gree's unity-webview in EditorWindow
# https://github.com/gree/unity-webview

using UnityEditor;
using UnityEngine;

public class WebViewEditorWindow : EditorWindow
{
    static GameObject go;
    static WebViewObject wvo;

    [MenuItem("Window/UnityWebViewTwitter")]
    static void Open()
    {

        var win = CreateInstance<WebViewEditorWindow>();
        win.minSize = new Vector2(Screen.width, Screen.height + 32);
        win.maxSize = new Vector2(Screen.width, Screen.height + 32);

        go = EditorUtility.CreateGameObjectWithHideFlags("wvo", HideFlags.HideAndDontSave);

        wvo = go.AddComponent<WebViewObject>();
        wvo.Init(
            ld: (msg) =>
            {
                Debug.Log(string.Format("CallOnLoaded[{0}]", msg));
            });
        wvo.SetMargins(0, 0, 0, 0);
        wvo.SetVisibility(true);
        wvo.LoadURL("https://mobile.twitter.com");

        win.Show();
    } 

    void OnDestroy()
    {
        DestroyImmediate(go);
        wvo = null;
        go = null;
    }

    void OnGUI()
    {
        if (wvo != null)
        {
            wvo.OnGUI();
        }
    }
}