Enable surprise me wallpaper for new profiles.

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;
 
 var surpriseWallpaper = null;
@@ skipping 195 matching lines @@
 /**
  * Calculates when the next wallpaper change should be triggered.
  * @param {Date} now Current time.
  * @return {number} The time when next wallpaper change should happen.
  */
 SurpriseWallpaper.prototype.nextUpdateTime = function(now) {
   var nextUpdate = new Date(now.setDate(now.getDate() + 1)).toDateString();
   return new Date(nextUpdate).getTime();
 };
 
+/**
+ * Enables surprise me wallpaper.
+ */
+SurpriseWallpaper.prototype.enableSurpriseMe = function() {
+  Constants.WallpaperSyncStorage.get(Constants.AccessSurpriseMeEnabledKey,
+                                     function(items) {
+    if (!items.hasProperty(Constants.AccessSurpriseMeEnabledKey) ||
+        !items[Constants.AccessSurpriseMeEnabledKey]) {
+      WallpaperUtil.saveToStorage(Constants.AccessSurpriseMeEnabledKey,
+                                  true, true, NULL);
+    }
+  });
+};
+
 chrome.app.runtime.onLaunched.addListener(function() {
   if (wallpaperPickerWindow && !wallpaperPickerWindow.contentWindow.closed) {
     wallpaperPickerWindow.focus();
     chrome.wallpaperPrivate.minimizeInactiveWindows();
     return;
   }
 
   chrome.app.window.create('main.html', {
     frame: 'none',
     width: WALLPAPER_PICKER_WIDTH,
@@ skipping 44 matching lines @@
         WallpaperUtil.saveToStorage(Constants.AccessLocalWallpaperInfoKey,
                                     newValue, false);
       }
     });
   }
 });
 
 chrome.alarms.onAlarm.addListener(function() {
   SurpriseWallpaper.getInstance().next();
 });