chrome/browser/resources/downloads/downloads.js

// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

function loadDownloads() {
  return HTMLImports.whenReady(function() {
    downloads.Manager.onLoad().then(function() {
      requestIdleCallback(function() {
        chrome.send(
            'metricsHandler:recordTime',
            ['Download.ResultsRenderedTime', window.performance.now()]);
        document.fonts.load('bold 12px Roboto');
      });
    });
  });
}

if (document.readyState === 'complete') {
  loadDownloads();
} else {
  window.addEventListener('load', loadDownloads);
}