Youtube title changer (match video chapter) | Custom script

script.js

// ==UserScript==
// @name         Title Changer
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  try to take over the world!
// @author       You
// @match        https://www.youtube.com/watch*
// @icon         https://www.google.com/s2/favicons?sz=64&domain=youtube.com
// @grant        none
// ==/UserScript==

(function() {
    'use strict';
    setInterval(main, 1000);
})();

function main()
{
    let els = document.querySelector('.ytp-chapter-title-content');
    if (!els) return;
    let title = els.textContent;
    if (!title) return
    if (window.document.title === title) return;
    window.document.title = title;
    if ('mediaSession' in navigator) {

        navigator.mediaSession.metadata = new MediaMetadata({
            title: title,
        });
    }
}