MD Settings: Restore focus after exiting Content settings sub-subpages.

chrome/browser/resources/settings/site_settings_page/site_settings_page.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/paper-icon-button/paper-icon-button-light.html">
 <link rel="import" href="../icons.html">
 <link rel="import" href="../route.html">
 <link rel="import" href="../settings_shared_css.html">
 <link rel="import" href="../site_settings/constants.html">
 <link rel="import" href="../site_settings/site_settings_behavior.html">
 <link rel="import" href="../site_settings/site_settings_prefs_browser_proxy.html">
 
 <dom-module id="settings-site-settings-page">
   <template>
     <style include="settings-shared">
       .settings-box iron-icon + .middle {
         -webkit-padding-start: 20px;
       }
     </style>
     <template is="dom-if" if="[[enableSiteSettings_]]">
       <div class="settings-box first" category$="[[ALL_SITES]]"
           data-route="SITE_SETTINGS_ALL" on-tap="onTapNavigate_" actionable>
         <iron-icon icon="settings:list"></iron-icon>
         <div class="middle">$i18n{siteSettingsCategoryAllSites}</div>
         <button class="subpage-arrow" is="paper-icon-button-light"
             aria-label="$i18n{siteSettingsCategoryAllSites}"></button>
       </div>
       <div class="settings-box line-only">
       </div>
     </template>
-    <div class="settings-box two-line first"
+    <div id="cookies" class="settings-box two-line first"
         category$="[[ContentSettingsTypes.COOKIES]]"
         data-route="SITE_SETTINGS_COOKIES" on-tap="onTapNavigate_" actionable>
       <iron-icon icon="settings:cookie"></iron-icon>
       <div class="middle">
         $i18n{siteSettingsCookies}
         <div class="secondary" id="cookiesSecondary">
           [[defaultSettingLabel_(
               default_.cookies,
               '$i18nPolymer{siteSettingsCookiesAllowed}',
               '$i18nPolymer{siteSettingsBlocked}',
               '$i18nPolymer{deleteDataPostSession}')]]
         </div>
       </div>
       <button class="subpage-arrow" is="paper-icon-button-light"
           aria-label="$i18n{siteSettingsCookies}"
           aria-describedby="cookiesSecondary"></button>
     </div>
-    <div class="settings-box two-line"
+    <div id="location" class="settings-box two-line"
         category$="[[ContentSettingsTypes.GEOLOCATION]]"
         data-route="SITE_SETTINGS_LOCATION" on-tap="onTapNavigate_" actionable>
       <iron-icon icon="settings:location-on"></iron-icon>
       <div class="middle">
         $i18n{siteSettingsLocation}
         <div class="secondary" id="locationSecondary">
           [[defaultSettingLabel_(
               default_.location,
               '$i18nPolymer{siteSettingsAskBeforeAccessing}',
               '$i18nPolymer{siteSettingsBlocked}')]]
         </div>
       </div>
       <button class="subpage-arrow" is="paper-icon-button-light"
           aria-label="$i18n{siteSettingsLocation}"
           aria-describedby="locationSecondary"></button>
     </div>
-    <div class="settings-box two-line"
+    <div id="camera" class="settings-box two-line"
         category$="[[ContentSettingsTypes.CAMERA]]"
         data-route="SITE_SETTINGS_CAMERA"
         on-tap="onTapNavigate_" actionable>
       <iron-icon icon="settings:videocam"></iron-icon>
       <div class="middle">
         $i18n{siteSettingsCamera}
         <div class="secondary" id="cameraSecondary">
           [[defaultSettingLabel_(
               default_.mediaStreamCamera,
               '$i18nPolymer{siteSettingsAskBeforeAccessing}',
               '$i18nPolymer{siteSettingsBlocked}')]]
         </div>
       </div>
       <button class="subpage-arrow" is="paper-icon-button-light"
           aria-label="$i18n{siteSettingsCamera}"
           aria-describedby="cameraSecondary"></button>
     </div>
-    <div class="settings-box two-line" category$="[[ContentSettingsTypes.MIC]]"
+    <div id="microphone" class="settings-box two-line"
+        category$="[[ContentSettingsTypes.MIC]]"
         data-route="SITE_SETTINGS_MICROPHONE" on-tap="onTapNavigate_"
         actionable>
       <iron-icon icon="settings:mic"></iron-icon>
       <div class="middle">
         $i18n{siteSettingsMic}
         <div class="secondary" id="micSecondary">
           [[defaultSettingLabel_(
               default_.mediaStreamMic,
               '$i18nPolymer{siteSettingsAskBeforeAccessing}',
               '$i18nPolymer{siteSettingsBlocked}')]]
         </div>
       </div>
       <button class="subpage-arrow" is="paper-icon-button-light"
           aria-label="$i18n{siteSettingsMic}"
           aria-describedby="micSecondary"></button>
     </div>
-    <div class="settings-box two-line"
+    <div id="notifications" class="settings-box two-line"
         category$="[[ContentSettingsTypes.NOTIFICATIONS]]"
         data-route="SITE_SETTINGS_NOTIFICATIONS" on-tap="onTapNavigate_"
         actionable>
       <iron-icon icon="settings:notifications"></iron-icon>
       <div class="middle">
         $i18n{siteSettingsNotifications}
         <div class="secondary" id="notificationsSecondary">
           [[defaultSettingLabel_(
               default_.notifications,
               '$i18nPolymer{siteSettingsAskBeforeSending}',
               '$i18nPolymer{siteSettingsBlocked}')]]
         </div>
       </div>
       <button class="subpage-arrow" is="paper-icon-button-light"
           aria-label="$i18n{siteSettingsNotifications}"
           aria-describedby="notificationsSecondary"></button>
     </div>
-    <div class="settings-box two-line"
+    <div id="javascript" class="settings-box two-line"
         category$="[[ContentSettingsTypes.JAVASCRIPT]]"
         data-route="SITE_SETTINGS_JAVASCRIPT" on-tap="onTapNavigate_"
         actionable>
       <iron-icon icon="settings:input"></iron-icon>
       <div class="middle">
         $i18n{siteSettingsJavascript}
         <div class="secondary" id="javascriptSecondary">
           [[defaultSettingLabel_(
               default_.javascript,
               '$i18nPolymer{siteSettingsAllowed}',
               '$i18nPolymer{siteSettingsBlocked}')]]
         </div>
       </div>
       <button class="subpage-arrow" is="paper-icon-button-light"
           aria-label="$i18n{siteSettingsJavascript}"
           aria-describedby="javascriptSecondary"></button>
     </div>
-    <div class="settings-box two-line"
+    <div id="flash" class="settings-box two-line"
         category$="[[ContentSettingsTypes.PLUGINS]]"
         data-route="SITE_SETTINGS_FLASH" on-tap="onTapNavigate_" actionable>
       <iron-icon icon="cr:extension"></iron-icon>
       <div class="middle">
         $i18n{siteSettingsFlash}
         <div class="secondary" id="flashSecondary">
           [[defaultSettingLabel_(
               default_.plugins,
               '$i18nPolymer{siteSettingsFlashAllow}',
               '$i18nPolymer{siteSettingsFlashBlock}',
               '$i18nPolymer{siteSettingsFlashAskBefore}')]]
         </div>
       </div>
       <button class="subpage-arrow" is="paper-icon-button-light"
           aria-label="$i18n{siteSettingsFlash}"
           aria-describedby="flashSecondary"></button>
     </div>
-    <div class="settings-box two-line"
+    <div id="images" class="settings-box two-line"
         category$="[[ContentSettingsTypes.IMAGES]]"
         data-route="SITE_SETTINGS_IMAGES" on-tap="onTapNavigate_" actionable>
       <iron-icon icon="settings:photo"></iron-icon>
       <div class="middle">
         $i18n{siteSettingsImages}
         <div class="secondary" id="imagesSecondary">
           [[defaultSettingLabel_(
               default_.images,
               '$i18nPolymer{siteSettingsShowAll}',
               '$i18nPolymer{siteSettingsDontShowImages}')]]
         </div>
       </div>
       <button class="subpage-arrow" is="paper-icon-button-light"
           aria-label="$i18n{siteSettingsImages}"
           aria-describedby="imagesSecondary"></button>
     </div>
-    <div category$="[[ContentSettingsTypes.POPUPS]]"
+    <div id="popups" category$="[[ContentSettingsTypes.POPUPS]]"
         class="settings-box two-line" data-route="SITE_SETTINGS_POPUPS"
         on-tap="onTapNavigate_" actionable>
       <iron-icon icon="cr:open-in-new"></iron-icon>
       <div class="middle">
         $i18n{siteSettingsPopups}
         <div class="secondary" id="popupsSecondary">
           [[defaultSettingLabel_(
               default_.popups,
               '$i18nPolymer{siteSettingsAllowed}',
               '$i18nPolymer{siteSettingsBlocked}')]]
         </div>
       </div>
       <button class="subpage-arrow" is="paper-icon-button-light"
           aria-label="$i18n{siteSettingsPopups}"
           aria-describedby="popupsSecondary"></button>
     </div>
     <template is="dom-if" if="[[enableSafeBrowsingSubresourceFilter_]]">
-      <div class="settings-box two-line"
+      <div id="subresource-filter" class="settings-box two-line"
           category$="[[ContentSettingsTypes.SUBRESOURCE_FILTER]]"
           data-route="SITE_SETTINGS_SUBRESOURCE_FILTER" on-tap="onTapNavigate_"
           actionable>
         <iron-icon icon="cr:open-in-new"></iron-icon>
         <div class="middle">
           $i18n{siteSettingsSubresourceFilter}
           <div class="secondary" id="subresourceFilterSecondary">
             [[defaultSettingLabel_(
                 default_.subresourceFilter,
                 '$i18nPolymer{siteSettingsSubresourceFilterBlock}',
                 '$i18nPolymer{siteSettingsSubresourceFilterAllow}')]]
           </div>
         </div>
         <button class="subpage-arrow" is="paper-icon-button-light"
             aria-label="$i18n{siteSettingsSubresourceFilter}"
             aria-describedby="subresourceFilterSecondary"></button>
       </div>
     </template>
-    <div class="settings-box two-line"
+    <div id="background-sync" class="settings-box two-line"
         category$="[[ContentSettingsTypes.BACKGROUND_SYNC]]"
         data-route="SITE_SETTINGS_BACKGROUND_SYNC" on-tap="onTapNavigate_"
         actionable>
       <iron-icon icon="settings:sync"></iron-icon>
       <div class="middle">
         $i18n{siteSettingsBackgroundSync}
         <div class="secondary" id="backgroundSyncSecondary">
           [[defaultSettingLabel_(
               default_.backgroundSync,
               '$i18nPolymer{siteSettingsAllowRecentlyClosedSites}',
               '$i18nPolymer{siteSettingsBackgroundSyncBlocked}')]]
         </div>
       </div>
       <button class="subpage-arrow" is="paper-icon-button-light"
           aria-label="$i18n{siteSettingsBackgroundSync}"
           aria-describedby="backgroundSyncSecondary"></button>
     </div>
-    <div class="settings-box two-line"
+    <div id="automatic-downloads" class="settings-box two-line"
         category$="[[ContentSettingsTypes.AUTOMATIC_DOWNLOADS]]"
         data-route="SITE_SETTINGS_AUTOMATIC_DOWNLOADS"
         on-tap="onTapNavigate_" actionable>
       <iron-icon icon="cr:file-download"></iron-icon>
       <div class="middle">
         $i18n{siteSettingsAutomaticDownloads}
         <div class="secondary" id="automaticDownloadsSecondary">
           [[defaultSettingLabel_(
               default_.multipleAutomaticDownloads,
               '$i18nPolymer{siteSettingsAutoDownloadAsk}',
               '$i18nPolymer{siteSettingsAutoDownloadBlock}')]]
         </div>
       </div>
       <button class="subpage-arrow" is="paper-icon-button-light"
           aria-label="$i18n{siteSettingsAutomaticDownloads}"
           aria-describedby="automaticDownloadsSecondary"></button>
     </div>
-    <div class="settings-box two-line"
+    <div id="unsandboxed-plugins" class="settings-box two-line"
         category$="[[ContentSettingsTypes.UNSANDBOXED_PLUGINS]]"
         data-route="SITE_SETTINGS_UNSANDBOXED_PLUGINS"
         on-tap="onTapNavigate_" actionable>
       <iron-icon icon="cr:extension"></iron-icon>
       <div class="middle">
         $i18n{siteSettingsUnsandboxedPlugins}
         <div class="secondary" id="unsandboxedPluginsSecondary">
           [[defaultSettingLabel_(
               default_.ppapiBroker,
               '$i18nPolymer{siteSettingsUnsandboxedPluginsAsk}',
               '$i18nPolymer{siteSettingsUnsandboxedPluginsBlock}')]]
         </div>
       </div>
       <button class="subpage-arrow" is="paper-icon-button-light"
           aria-label="$i18n{siteSettingsUnsandboxedPlugins}"
           aria-describedby="unsandboxedPluginsSecondary"></button>
     </div>
     <template is="dom-if" if="[[!isGuest_]]">
-      <div class="settings-box two-line"
+      <div id="protocol-handlers" class="settings-box two-line"
           category$="[[ContentSettingsTypes.PROTOCOL_HANDLERS]]"
           data-route="SITE_SETTINGS_HANDLERS"
           on-tap="onTapNavigate_" actionable>
         <iron-icon icon="settings:protocol-handler"></iron-icon>
         <div class="middle">
           $i18n{siteSettingsHandlers}
           <div class="secondary" id="handlersSecondary">
             [[defaultSettingLabel_(
                 default_.registerProtocolHandler,
                 '$i18nPolymer{siteSettingsHandlersAsk}',
                 '$i18nPolymer{siteSettingsHandlersBlocked}')]]
           </div>
         </div>
         <button class="subpage-arrow" is="paper-icon-button-light"
             aria-label="$i18n{siteSettingsHandlers}"
             aria-describedby="handlersSecondary"></button>
       </div>
     </template>
-    <div class="settings-box two-line"
+    <div id="midi-devices" class="settings-box two-line"
         category$="[[ContentSettingsTypes.MIDI_DEVICES]]"
         data-route="SITE_SETTINGS_MIDI_DEVICES"
         on-tap="onTapNavigate_" actionable>
       <iron-icon icon="settings:music-note"></iron-icon>
       <div class="middle">
         $i18n{siteSettingsMidiDevices}
         <div class="secondary" id="midiDevicesSecondary">
           [[defaultSettingLabel_(
               default_.midiSysex,
               '$i18nPolymer{siteSettingsMidiDevicesAsk}',
               '$i18nPolymer{siteSettingsMidiDevicesBlock}')]]
         </div>
       </div>
       <button class="subpage-arrow" is="paper-icon-button-light"
           aria-label="$i18n{siteSettingsMidiDevices}"
           aria-describedby="midiDevicesSecondary"></button>
     </div>
-    <div class="settings-box" category$="[[ContentSettingsTypes.ZOOM_LEVELS]]"
-        data-route="SITE_SETTINGS_ZOOM_LEVELS"
-        on-tap="onTapNavigate_" actionable>
+    <div id="zoom-levels" class="settings-box"
+        category$="[[ContentSettingsTypes.ZOOM_LEVELS]]"
+        data-route="SITE_SETTINGS_ZOOM_LEVELS" on-tap="onTapNavigate_"
+        actionable>
       <iron-icon icon="settings:zoom-in"></iron-icon>
       <div class="middle">$i18n{siteSettingsZoomLevels}</div>
       <button class="subpage-arrow" is="paper-icon-button-light"
           aria-label="$i18n{siteSettingsZoomLevels}"></button>
     </div>
-    <div class="settings-box" category$="[[ContentSettingsTypes.USB_DEVICES]]"
-        data-route="SITE_SETTINGS_USB_DEVICES"
-        on-tap="onTapNavigate_" actionable>
+    <div id="usb-devices" class="settings-box"
+        category$="[[ContentSettingsTypes.USB_DEVICES]]"
+        data-route="SITE_SETTINGS_USB_DEVICES" on-tap="onTapNavigate_"
+        actionable>
       <iron-icon icon="settings:usb"></iron-icon>
       <div class="middle">$i18n{siteSettingsUsbDevices}</div>
       <button class="subpage-arrow" is="paper-icon-button-light"
           aria-label="$i18n{siteSettingsUsbDevices}"></button>
     </div>
-    <div class="settings-box" data-route="SITE_SETTINGS_PDF_DOCUMENTS"
-        on-tap="onTapNavigate_" actionable>
+    <div id="pdf-documents" class="settings-box"
+        data-route="SITE_SETTINGS_PDF_DOCUMENTS" on-tap="onTapNavigate_"
+        actionable>
       <iron-icon icon="settings:pdf"></iron-icon>
       <div class="middle">$i18n{siteSettingsPdfDocuments}</div>
       <button class="subpage-arrow" is="paper-icon-button-light"
           aria-label="$i18n{siteSettingsPdfDocuments}"></button>
     </div>
-    <div class="settings-box" data-route="SITE_SETTINGS_PROTECTED_CONTENT"
-        on-tap="onTapNavigate_" actionable>
+    <div id="protected-content" class="settings-box"
+        data-route="SITE_SETTINGS_PROTECTED_CONTENT" on-tap="onTapNavigate_"
+        actionable>
       <iron-icon icon="settings:security"></iron-icon>
       <div class="middle">$i18n{siteSettingsProtectedContent}</div>
       <button class="subpage-arrow" is="paper-icon-button-light"
           aria-label="$i18n{siteSettingsProtectedContent}"></button>
     </div>
   </template>
   <script src="site_settings_page.js"></script>
 </dom-module>