Tempermoney: 2x or 3x while pressing down a key in Youtube

gistfile1.txt

// ==UserScript==
// @name         Speed up video
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  try to take over the world!
// @author       You
// @match        https://www.youtube.com/watch?*
// @grant        none
// ==/UserScript==

(function() {
    function getSpeed() { return document.getElementsByClassName('html5-main-video')[0].playbackRate };
    function setSpeed(rate) { document.getElementsByClassName('html5-main-video')[0].playbackRate = rate };

    var speed = getSpeed();
    var prevSpeed = getSpeed();
    var override = false;
    document.onkeydown = function(e) {
        if (e.which == 221){  // ']' key
            if (!override) {
                override = true;
                console.log('KeyDown! Speed 2x');
                prevSpeed = getSpeed();
                setSpeed(2);
            }
        }
        if (e.which == 220){  // '\' key
            if (!override) {
                override = true;
                console.log('KeyDown! Speed 3x');
                prevSpeed = getSpeed();
                setSpeed(3);
            }
        }
    }
    document.onkeyup = function(e) {
        if (e.which == 221 || e.which == 220) {
            if (override) {
                override = false;
                console.log('Keyup! Resume prev speed');
                setSpeed(prevSpeed);
            }
        }
    }
})();