Enable user change background image in settings page in Aura build.

chrome/browser/chromeos/login/user_manager.h

 // Copyright (c) 2012 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_LOGIN_USER_MANAGER_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_USER_MANAGER_H_
 #pragma once
 
 #include <string>
 
@@ skipping 81 matching lines @@
   // Save user's displayed (non-canonical) email in local state preferences.
   // Ignored If there is no such user.
   void SaveUserDisplayEmail(const std::string& username,
                             const std::string& display_email);
 
   // Returns the display email for user |username| if it is known (was
   // previously set by a |SaveUserDisplayEmail| call).
   // Otherwise, returns |username| itself.
   std::string GetUserDisplayEmail(const std::string& username) const;
 
+  int GetUserWallpaper(const std::string& username);
+  void SetUserWallpaper(const std::string& username,
+                        int wallpaper_index);
+
   // Sets user image to the default image with index |image_index|, sends
   // LOGIN_USER_IMAGE_CHANGED notification and updates Local State.
   void SaveUserDefaultImageIndex(const std::string& username, int image_index);
 
   // Saves image to file, sends LOGIN_USER_IMAGE_CHANGED notification and
   // updates Local State.
   void SaveUserImage(const std::string& username, const SkBitmap& image);
 
   // Tries to load user image from disk; if successful, sets it for the user,
   // sends LOGIN_USER_IMAGE_CHANGED notification and updates Local State.
@@ skipping 205 matching lines @@
 
   // Data URL for |downloaded_profile_image_|.
   std::string downloaded_profile_image_data_url_;
 
   DISALLOW_COPY_AND_ASSIGN(UserManager);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_USER_MANAGER_H_