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

chrome/browser/resources/help/help_page.js

Index: chrome/browser/resources/help/help_page.js
diff --git a/chrome/browser/resources/help/help_page.js b/chrome/browser/resources/help/help_page.js
index 10a1807a93a813abd2386e450a635a8c2ad52c0b..d7cf0b78c51240c1c9fe4ae1524c8650007fcc90 100644
--- a/chrome/browser/resources/help/help_page.js
+++ b/chrome/browser/resources/help/help_page.js
@@ -11,8 +11,9 @@ cr.define('help', function() {
    * 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);
@@ -143,23 +144,40 @@ cr.define('help', function() {
       chrome.send('onPageLoaded');
     },
 
+    /** @override */
+    didClosePage: function() {
+      this.setMoreInfoVisible_(false);
+    },
+
     /**
-     * Toggles the visible state of the 'More Info' section.
+     * Sets the visible state of the 'More Info' section.
+     * @param {boolean} visible Whether the section should be visible.
      * @private
      */
-    toggleMoreInfo_: function() {
+    setMoreInfoVisible_: function(visible) {
       var moreInfo = $('more-info-container');
-      var visible = moreInfo.className == 'visible';
-      moreInfo.className = visible ? '' : 'visible';
-      moreInfo.style.height = visible ? '' : moreInfo.scrollHeight + 'px';
+      if (visible == moreInfo.classList.contains('visible'))
+        return;
+
+      moreInfo.classList.toggle('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');
+            loadTimeData.getString('hideMoreInfo') :
+            loadTimeData.getString('showMoreInfo');
       });
     },
 
     /**
+     * Toggles the visible state of the 'More Info' section.
+     * @private
+     */
+    toggleMoreInfo_: function() {
+      var moreInfo = $('more-info-container');
+      this.setMoreInfoVisible_(!moreInfo.classList.contains('visible'));
+    },
+
+    /**
      * 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.