components/sync/driver/resources/sync_index.js

// Copyright (c) 2011 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.

// Allow platform specific CSS rules.
//
// TODO(akalin): BMM and options page does something similar, too.
// Move this to util.js.
if (cr.isWindows)
  document.documentElement.setAttribute('os', 'win');

cr.ui.decorate('tabbox', cr.ui.TabBox);

cr.define('chrome.sync.index', function() {
  function setUserEventsTabVisibility(visible) {
    $('sync-user-events-tab').hidden = !visible;
  }

  function onLoad() {
    chrome.sync.userEventsVisibilityCallback = setUserEventsTabVisibility;
    chrome.sync.requestUserEventsVisibility();
  }

  return {
    onLoad: onLoad
  };
});

document.addEventListener('DOMContentLoaded', chrome.sync.index.onLoad, false);