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 id = loadTimeData.valueExists('aboutOverlayTabTitle') ?
+      'aboutOverlayTabTitle' : 'aboutTitle';
+    Page.call(this, 'help', loadTimeData.getString(id), 'help-page');
   }
 
   cr.addSingletonGetter(HelpPage);
 
   HelpPage.prototype = {
     __proto__: Page.prototype,
 
     /**
      * True if after update powerwash button should be displayed.
      * @private
@@ skipping 110 matching lines @@
                                  $('channel-change-disallowed-icon'),
                                  $('help-container'),
                                  cr.ui.ArrowLocation.TOP_END);
         };
       }
 
       // Attempt to update.
       chrome.send('onPageLoaded');
     },
 
+    /** @override */
+    didClosePage: function() {
+      this.setMoreInfoVisible_(false);
+    },
+
+    /**
+     * Sets the visible state of the 'More Info' section.
+     * @param {boolean} visible Whether the section should be visible.
+     * @private
+     */
+    setMoreInfoVisible_: function(visible) {
+      var moreInfo = $('more-info-container');
+      if ((visible && moreInfo.classList.contains('visible')) ||
+          !visible && !moreInfo.classList.contains('visible')) {
+        return;
+      }

[Dan Beam, 2014/08/13 22:26:18]

if (visible == moreInfo.classList.contains('visible'))
  return;

[michaelpg, 2014/08/14 11:43:55]

Done.

+
+      if (visible)
+        moreInfo.classList.add('visible');
+      else
+        moreInfo.classList.remove('visible');

[Dan Beam, 2014/08/13 22:26:18]

moreInfo.classList.toggle('visible', visible);

[michaelpg, 2014/08/14 11:43:55]

Done.

+      moreInfo.style.height = visible ? moreInfo.scrollHeight + 'px' : '';
+      moreInfo.addEventListener('webkitTransitionEnd', function(event) {
+        $('more-info-expander').textContent = visible ?
+            loadTimeData.getString('hideMoreInfo') :
+            loadTimeData.getString('showMoreInfo');
+      });
+    },
+
     /**
      * 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) {
-        $('more-info-expander').textContent = visible ?
-            loadTimeData.getString('showMoreInfo') :
-            loadTimeData.getString('hideMoreInfo');
-      });
+      var visible = moreInfo.classList.contains('visible');
+      this.setMoreInfoVisible_(!visible);

[Dan Beam, 2014/08/13 22:26:18]

nit:
      this.setMoreInfoVisible_(!moreInfo.classList.contains('visible'));

[michaelpg, 2014/08/14 11:43:55]

Done.

     },
 
     /**
      * Assigns |method| to the onclick property of |el| if |el| exists.
      * @param {HTMLElement} el The element on which to set the click handler.
      * @param {function} method The click handler.
      * @private
      */
     maybeSetOnClick_: function(el, method) {
       if (el)
@@ skipping 339 matching lines @@
 
   HelpPage.updateChannelChangePageContainerVisibility = function() {
     HelpPage.getInstance().updateChannelChangePageContainerVisibility_();
   };
 
   // Export
   return {
     HelpPage: HelpPage
   };
 });