MD Settings: rework how advanced UI shows

chrome/browser/resources/settings/settings_menu/settings_menu.html

Index: chrome/browser/resources/settings/settings_menu/settings_menu.html
diff --git a/chrome/browser/resources/settings/settings_menu/settings_menu.html b/chrome/browser/resources/settings/settings_menu/settings_menu.html
index abd0493712b38839c8c0963cc66f7ddcab24de89..2b55a9b720553c15d99a2d75677860068be5fff4 100644
--- a/chrome/browser/resources/settings/settings_menu/settings_menu.html
+++ b/chrome/browser/resources/settings/settings_menu/settings_menu.html
@@ -136,11 +136,11 @@
         </paper-menu>
       </div>
       <paper-submenu class="page-menu" id="advancedPage" actionable
-          opened="{{advancedOpened_}}"
+          opened="{{advancedOpened}}"
           hidden="[[!pageVisibility.advancedSettings]]">
         <div class="menu-trigger">
           <span>$i18n{advancedPageTitle}</span>
-          <iron-icon icon="[[arrowState_(advancedOpened_)]]"></iron-icon>
+          <iron-icon icon="[[arrowState_(advancedOpened)]]"></iron-icon>
           <paper-ripple></paper-ripple>
         </div>
         <paper-menu attr-for-selected="data-path" class="menu-content"