Integrate About page into Settings for Chrome OS settings in a window.

chrome/browser/resources/help/help_page.js

 // Copyright 2014 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.
 
 cr.define('help', function() {
   var Page = cr.ui.pageManager.Page;
   var PageManager = cr.ui.pageManager.PageManager;
 
   /**
    * Encapsulated handling of the About page. Called 'help' internally to avoid
    * confusion with generic AboutUI (about:memory, about:sandbox, etc.).
    */
   function HelpPage() {
-    Page.call(this, 'help', loadTimeData.getString('aboutTitle'),
-              'help-page');
+    var title;
+    if (loadTimeData.valueExists('aboutOverlayTabTitle'))
+      title = loadTimeData.getString('aboutOverlayTabTitle');
+    else
+      title = loadTimeData.getString('aboutTitle');
+    Page.call(this, 'help', title, 'help-page');
   }
 
   cr.addSingletonGetter(HelpPage);
 
   HelpPage.prototype = {
     __proto__: Page.prototype,
 
     /**
      * True if after update powerwash button should be displayed.
      * @private
@@ skipping 81 matching lines @@
 
       if (cr.isChromeOS) {
         // Add event listener for the close button when shown as an overlay.
         if ($('about-done')) {
           $('about-done').addEventListener('click', function() {
             PageManager.closeOverlay();
           });
         }
 
         $('change-channel').onclick = function() {
-          PageManager.showPageByName('channel-change-page', false);

[Dan Beam, 2014/08/07 22:36:16]

?

[michaelpg, 2014/08/08 01:10:46]

the default for updateHistory is true. I don't see why this should be using
false. 

[Dan Beam, 2014/08/08 02:39:13]

sometimes when showing dialogs we *don't* want a history entry (e.g. a confirm
dialog for a contextual action that can't be undone)

+          PageManager.showPageByName('channel-change-page');
         };
 
         var channelChangeDisallowedError = document.createElement('div');
         channelChangeDisallowedError.className = 'channel-change-error-bubble';
 
         var channelChangeDisallowedIcon = document.createElement('div');
         channelChangeDisallowedIcon.classList.add('help-page-icon-large');
         channelChangeDisallowedIcon.classList.add('channel-change-error-icon');
         channelChangeDisallowedError.appendChild(channelChangeDisallowedIcon);
 
         var channelChangeDisallowedText = document.createElement('div');
         channelChangeDisallowedText.className = 'channel-change-error-text';
         channelChangeDisallowedText.textContent =
             loadTimeData.getString('channelChangeDisallowedMessage');
         channelChangeDisallowedError.appendChild(channelChangeDisallowedText);
 
         $('channel-change-disallowed-icon').onclick = function() {
           PageManager.showBubble(channelChangeDisallowedError,
                                  $('channel-change-disallowed-icon'),
                                  $('help-container'),
                                  cr.ui.ArrowLocation.TOP_END);
         };
       }
 
       // Attempt to update.
       chrome.send('onPageLoaded');
     },
 
+    /** @override */
+    didClosePage: function() {
+      if ($('more-info-container').classList.contains('visible'))
+        this.toggleMoreInfo_();
+    },
+
     /**
      * Toggles the visible state of the 'More Info' section.
      * @private
      */
     toggleMoreInfo_: function() {
       var moreInfo = $('more-info-container');
       var visible = moreInfo.className == 'visible';
       moreInfo.className = visible ? '' : 'visible';
       moreInfo.style.height = visible ? '' : moreInfo.scrollHeight + 'px';
       moreInfo.addEventListener('webkitTransitionEnd', function(event) {
@@ skipping 353 matching lines @@
 
   HelpPage.updateChannelChangePageContainerVisibility = function() {
     HelpPage.getInstance().updateChannelChangePageContainerVisibility_();
   };
 
   // Export
   return {
     HelpPage: HelpPage
   };
 });