Disable Delete option for custom wallpapers when 'Surprise Me' is enabled.

chrome/browser/resources/chromeos/wallpaper_manager/js/wallpaper_manager.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.
 
 /**
  * WallpaperManager constructor.
  *
  * WallpaperManager objects encapsulate the functionality of the wallpaper
  * manager extension.
  *
@@ skipping 184 matching lines @@
    * onChanged event. Event handler for that event is in event_page.js.
    * @private
    */
   WallpaperManager.prototype.toggleSurpriseMe_ = function() {
     var self = this;
     var checkbox = $('surprise-me').querySelector('#checkbox');
     var shouldEnable = !checkbox.classList.contains('checked');
     var onSuccess = function() {
       if (chrome.runtime.lastError == null) {
         if (shouldEnable) {
+          self.document_.body.removeAttribute('surprise-me-disabled');
           checkbox.classList.add('checked');
           // Hides the wallpaper set by message if there is any.
           $('wallpaper-set-by-message').textContent = '';
         } else {
           // Unchecking the "Surprise me" checkbox falls back to the previous
           // wallpaper before "Surprise me" was turned on.
           if (self.wallpaperGrid_.activeItem) {
             self.setSelectedWallpaper_(self.wallpaperGrid_.activeItem);
             self.onWallpaperChanged_(self.wallpaperGrid_.activeItem,
                                      self.currentWallpaper_);
           }
           checkbox.classList.remove('checked');
+          self.document_.body.setAttribute('surprise-me-disabled', '');
         }
         $('categories-list').disabled = shouldEnable;
         $('wallpaper-grid').disabled = shouldEnable;
       } else {
         // TODO(bshe): show error message to user.
         console.error('Failed to save surprise me option to chrome storage.');
       }
     };
 
     // To prevent the onChanged event being fired twice, we only save the value
@@ skipping 47 matching lines @@
     $('set-wallpaper-layout').addEventListener(
         'change', this.onWallpaperLayoutChanged_.bind(this));
 
     if (loadTimeData.valueExists('wallpaperAppName')) {
       $('wallpaper-set-by-message').textContent = loadTimeData.getStringF(
           'currentWallpaperSetByMessage', str('wallpaperAppName'));
     }
 
     if (this.enableOnlineWallpaper_) {
       var self = this;
+      self.document_.body.setAttribute('surprise-me-disabled', '');
       $('surprise-me').hidden = false;
       $('surprise-me').addEventListener('click',
                                         this.toggleSurpriseMe_.bind(this));
       var onSurpriseMeEnabled = function() {
         $('surprise-me').querySelector('#checkbox').classList.add('checked');
         $('categories-list').disabled = true;
         $('wallpaper-grid').disabled = true;
+        self.document_.body.removeAttribute('surprise-me-disabled');
       };
 
       WallpaperUtil.enabledSyncThemesCallback(function(syncEnabled) {
         // Surprise me has been moved from local to sync storage, prefer
         // values from sync, but if unset check local and update synced pref
         // if applicable.
         if (syncEnabled) {
           Constants.WallpaperSyncStorage.get(
               Constants.AccessSyncSurpriseMeEnabledKey, function(items) {
             if (items.hasOwnProperty(
@@ skipping 805 matching lines @@
       }
       this.wallpaperGrid_.dataModel = wallpapersDataModel;
       if (selectedItem) {
         this.wallpaperGrid_.selectedItem = selectedItem;
         this.wallpaperGrid_.activeItem = selectedItem;
       }
     }
   };
 
 })();