CS0144

Part of "Form1.cs":
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using CefSharp;
using CefSharp.WinForms;
using CefSharp.Handler;
using CefSharp.Example;

namespace vBrowser
{
    public partial class Form1 : MetroFramework.Forms.MetroForm
    {
        public Form1()
        {
            CefSettings settings = new CefSettings();
            settings.CachePath = Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData) + @"\vBrowser";
            CefSharp.Cef.Initialize(settings);
            browser.DownloadHandler = new IDownloadHandler(); // ERROR HERE

                        InitializeComponent();
            //webcontrol.BrowserSettings.ApplicationCache = CefSharp.CefState.Enabled;
        }

        public ChromiumWebBrowser browser;


"DownloadHandler.cs":
// Copyright © 2013 The CefSharp Authors. All rights reserved.
//
// Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.

using System;

namespace CefSharp.Example.Handlers
{
    public class DownloadHandler : IDownloadHandler
    {
        public event EventHandler<DownloadItem> OnBeforeDownloadFired;

        public event EventHandler<DownloadItem> OnDownloadUpdatedFired;

        public void OnBeforeDownload(IWebBrowser chromiumWebBrowser, IBrowser browser, DownloadItem downloadItem, IBeforeDownloadCallback callback)
        {
            OnBeforeDownloadFired?.Invoke(this, downloadItem);

            if (!callback.IsDisposed)
            {
                using (callback)
                {
                    callback.Continue(downloadItem.SuggestedFileName, showDialog: true);
                }
            }
        }

        public void OnDownloadUpdated(IWebBrowser chromiumWebBrowser, IBrowser browser, DownloadItem downloadItem, IDownloadItemCallback callback)
        {
            OnDownloadUpdatedFired?.Invoke(this, downloadItem);
        }
    }
}