[cros] Update wallpaper when displaying Gaia frame.

chrome/browser/chromeos/login/wallpaper_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_WALLPAPER_MANAGER_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_WALLPAPER_MANAGER_H_
 
 #include <string>
 
 #include "ash/desktop_background/desktop_background_resources.h"
@@ skipping 147 matching lines @@
   void SetUserWallpaperInfo(const std::string& username,
                             const WallpaperInfo& info,
                             bool is_persistent);
 
   // Sets last selected user on user pod row.
   void SetLastSelectedUser(const std::string& last_selected_user);
 
   // Sets |email|'s wallpaper.
   void SetUserWallpaper(const std::string& email);
 
+  // Sets the default wallpaper for the sign-in screen.
+  void SetSigninWallpaper();
+
   // Sets wallpaper to |wallpaper|.
   void SetWallpaperFromImageSkia(const gfx::ImageSkia& wallpaper,
                                  ash::WallpaperLayout layout);
 
-  // User was deselected at login screen, reset wallpaper if needed.
-  void OnUserDeselected() {}
-
-  // User |email| was selected at login screen, load wallpaper.
-  void OnUserSelected(const std::string& email);
-
  private:
   typedef std::map<std::string, gfx::ImageSkia> CustomWallpaperMap;
 
   virtual ~WallpaperManager();
 
   // Change the wallpapers for users who choose DAILY wallpaper type. Updates
   // current wallpaper if it changed. This function should be called at exactly
   // at 0am if chromeos device is on.
   void BatchUpdateWallpaper();
 
@@ skipping 145 matching lines @@
   content::NotificationRegistrar registrar_;
 
   base::OneShotTimer<WallpaperManager> timer_;
 
   DISALLOW_COPY_AND_ASSIGN(WallpaperManager);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_WALLPAPER_MANAGER_H_