MD Settings: refactor some main page properties, fix Advanced toggle

chrome/browser/resources/settings/settings_main/settings_main.html

Index: chrome/browser/resources/settings/settings_main/settings_main.html
diff --git a/chrome/browser/resources/settings/settings_main/settings_main.html b/chrome/browser/resources/settings/settings_main/settings_main.html
index 990c85c6c2e61ce39e1eca9a1468443339875ca0..cd9239022e2d18962d77b332e60101eb23b3afae 100644
--- a/chrome/browser/resources/settings/settings_main/settings_main.html
+++ b/chrome/browser/resources/settings/settings_main/settings_main.html
@@ -38,23 +38,25 @@
       }
     </style>
     <content select="paper-icon-button"></content>
-    <template is="dom-if" if="[[showBasicPage_]]">
-      <settings-basic-page prefs="{{prefs}}" current-route="{{currentRoute}}">
-      </settings-basic-page>
-    </template>
-    <template is="dom-if" if="[[showAdvancedToggle_]]">
-      <div id="toggleSpacer"></div>
-      <div id="toggleContainer">
-        <div id="advancedToggle" on-tap="toggleAdvancedPage_">
-          <span>$i18n{advancedPageTitle}</span>
-          <iron-icon icon="[[arrowState_(showAdvancedPage_)]]"></iron-icon>
+    <template is="dom-if" if="[[!showAboutPage_]]">
+      <template is="dom-if" if="[[showBasicPage_]]">
+        <settings-basic-page prefs="{{prefs}}" current-route="{{currentRoute}}">
+        </settings-basic-page>
+      </template>
+      <div hidden$="[[inSubpage_]]">
+        <div id="toggleSpacer"></div>
+        <div id="toggleContainer">
+          <div id="advancedToggle" on-tap="toggleAdvancedPage_">
+            <span>$i18n{advancedPageTitle}</span>
+            <iron-icon icon="[[arrowState_(showAdvancedPage_)]]"></iron-icon>
+          </div>
         </div>
       </div>
-    </template>
-    <template is="dom-if" if="[[showAdvancedPage_]]">
-      <settings-advanced-page prefs="{{prefs}}"
-          current-route="{{currentRoute}}">
-      </settings-advanced-page>
+      <template is="dom-if" if="[[showAdvancedPage_]]">
+        <settings-advanced-page prefs="{{prefs}}"
+            current-route="{{currentRoute}}">
+        </settings-advanced-page>
+      </template>
     </template>
     <template is="dom-if" if="[[showAboutPage_]]">
       <settings-about-page current-route="{{currentRoute}}">