MD Settings: Ensure that "advanced sync page" is force rendered, only if applicable.

chrome/browser/resources/settings/people_page/people_page.html

 <link rel="import" href="chrome://resources/cr_elements/icons.html">
 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/html/web_ui_listener_behavior.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/neon-animation/neon-animatable.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-button/paper-button.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-checkbox/paper-checkbox.html">
 <link rel="import" href="chrome://resources/cr_elements/cr_dialog/cr_dialog.html">
 <link rel="import" href="/controls/settings_checkbox.html">
 <link rel="import" href="/people_page/sync_page.html">
 <link rel="import" href="/people_page/profile_info_browser_proxy.html">
@@ skipping 216 matching lines @@
 
         <template is="dom-if" if=[[profileManagesSupervisedUsers_]]>
           <div id="manageSupervisedUsersContainer" class="settings-box">
             <paper-button class="primary-button"
                 on-tap="onManageSupervisedUsers_">
               $i18n{manageSupervisedUsers}
             </paper-button>
           </div>
         </template>
       </neon-animatable>
-      <template is="dom-if" name="sync">
-        <settings-subpage
-            associated-control="[[$$('#customize-sync')]]"
-            page-title="$i18n{syncPageTitle}">
-          <settings-sync-page></settings-sync-page>
-        </settings-subpage>
+      <template is="dom-if" if="[[isAdvancedSyncSettingsVisible_(syncStatus)]]">

[dpapad, 2016/08/09 00:09:53]

See lines 129-132, where the element that triggers this subpage is also inside a
similar dom-if. Without this, the searching algorithm erroneously expands the
"advanced sync page" when it is not applicable (user is signed out), and an
assertion is thrown while searching by
https://cs.chromium.org/chromium/src/chrome/browser/resources/settings/search....

+        <template is="dom-if" name="sync">
+          <settings-subpage
+              associated-control="[[$$('#customize-sync')]]"
+              page-title="$i18n{syncPageTitle}">
+            <settings-sync-page></settings-sync-page>
+          </settings-subpage>
+        </template>
       </template>
 <if expr="chromeos">
       <template is="dom-if" name="quick-unlock-authenticate" no-search>
         <settings-subpage page-title="$i18n{quickUnlockTitle}">
           <settings-quick-unlock-authenticate
               set-modes="{{quickUnlockSetModes}}"
               profile-name="[[profileName_]]">
           </settings-quick-unlock-authenticate>
         </settings-subpage>
       </template>
@@ skipping 66 matching lines @@
 
 <if expr="chromeos">
     <template is="dom-if" if="[[easyUnlockEnabled_]]">
       <easy-unlock-turn-off-dialog id="easyUnlockTurnOffDialog">
       </easy-unlock-turn-off-dialog>
     </template>
 </if>
   </template>
   <script src="people_page.js"></script>
 </dom-module>