Hide/Show the checkmark in the Wallpaper Picker grid when 'Surprise Me' is enabled/disabled.

chrome/browser/resources/chromeos/wallpaper_manager/js/event_page.js

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 var WALLPAPER_PICKER_WIDTH = 574;
 var WALLPAPER_PICKER_HEIGHT = 420;
 
 var wallpaperPickerWindow = null;
 
 var surpriseWallpaper = null;
@@ skipping 316 matching lines @@
         var wpDocument = wallpaperPickerWindow.contentWindow.document;
         if (!!appName) {
           chrome.wallpaperPrivate.getStrings(function(strings) {
             var message =
                 strings.currentWallpaperSetByMessage.replace(/\$1/g, appName);
             wpDocument.querySelector('#wallpaper-set-by-message').textContent =
                 message;
             wpDocument.querySelector('#wallpaper-grid').classList.add('small');
             if (wpDocument.querySelector('.check'))
               wpDocument.querySelector('.check').style.visibility = 'hidden';
+            wpDocument.querySelector('#checkbox').classList.remove('checked');
+            wpDocument.querySelector('#categories-list').disabled = false;
+            wpDocument.querySelector('#wallpaper-grid').disabled = false;
           });
         } else {
           wpDocument.querySelector('#wallpaper-set-by-message').textContent =
               '';
           wpDocument.querySelector('#wallpaper-grid').classList.remove('small');
-          wpDocument.querySelector('.check').style.visibility = 'visible';
+          Constants.WallpaperSyncStorage.get(
+              Constants.AccessSyncSurpriseMeEnabledKey, function(item) {
+            var enable = item[Constants.AccessSyncSurpriseMeEnabledKey];
+            if (enable) {
+              wpDocument.querySelector('#checkbox').classList.add('checked');
+              if (wpDocument.querySelector('.check'))
+                wpDocument.querySelector('.check').style.visibility = 'hidden';
+            } else {
+              wpDocument.querySelector('#checkbox').classList.remove('checked');
+              if (wpDocument.querySelector('.check'))
+                wpDocument.querySelector('.check').style.visibility = 'visible';
+            }
+            wpDocument.querySelector('#categories-list').disabled = enable;
+            wpDocument.querySelector('#wallpaper-grid').disabled = enable;
+          });
         }
       };
 
       if (changes[Constants.AccessLocalWallpaperInfoKey]) {
         // If the old wallpaper is a third party wallpaper we should remove it
         // from the local & sync file system to free space.
         var oldInfo = changes[Constants.AccessLocalWallpaperInfoKey].oldValue;
         if (oldInfo &&
             oldInfo.url.indexOf(Constants.ThirdPartyWallpaperPrefix) != -1) {
           WallpaperUtil.deleteWallpaperFromLocalFS(oldInfo.url);
@@ skipping 101 matching lines @@
   SurpriseWallpaper.getInstance().disable();
 
   // Make third party wallpaper syncable through different devices.
   var filename = Constants.ThirdPartyWallpaperPrefix + new Date().getTime();
   var thumbnailFilename = filename + Constants.CustomWallpaperThumbnailSuffix;
   WallpaperUtil.storeWallpaperToSyncFS(filename, wallpaper);
   WallpaperUtil.storeWallpaperToSyncFS(thumbnailFilename, thumbnail);
   WallpaperUtil.saveWallpaperInfo(
       filename, layout, Constants.WallpaperSourceEnum.Custom, appName);
 });