Force auto close for tumblr share page

tumblr-share-auto-close.js

// ==UserScript==
// @name         auto-open-close-tumblr-share
// @namespace    http://k-ui.jp/
// @version      0.1
// @description
// @author       Keiichiro Ui
// @match        https://www.tumblr.com/widgets/share/tool*
// ==/UserScript==
/* jshint esnext: false */
/* jshint esversion: 6 */

function closer() {
    if (document.querySelector(".success-message")) {
        console.log("close");
        setTimeout(() => window.close(), 800);
    } else {
        requestAnimationFrame(closer);
    }
}
function poster() {
    const imgs = document.querySelectorAll(".photoset--cell [style*='pbs.twimg.com/']");
    if (imgs.length === 0) {
        setTimeout(() => poster(), 1000);
    } else if (imgs.length === 1) {
        setTimeout(() => document.querySelector('button.create_post_button').click(), 1000);
    } else {
        // noop; stop settimeout loop
    }
}
closer();
poster();