chromium/chrome/test/data/extensions/api_test/notifications/api/user_gesture/background.js

// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

const redDot = 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUA' +
    'AAAFCAYAAACNbyblAAAAHElEQVQI12P4//8/w38GIAXDIBKE0DHxgljNBAAO' +
    '9TXL0Y4OHwAAAABJRU5ErkJggg==';

function userActionTest() {
  chrome.test.sendMessage('');
}

chrome.notifications.onClicked.addListener(userActionTest);
chrome.notifications.onButtonClicked.addListener(userActionTest);
chrome.notifications.onClosed.addListener(userActionTest);

const options = {
  iconUrl: redDot,
  title: 'hi',
  message: 'there',
  type: 'basic',
  buttons: [{title: 'Button'}, {title: 'Button'}]
};

chrome.notifications.create('test', options, function() {});