[cros] Update wallpaper when displaying Gaia frame.

chrome/browser/chromeos/login/wallpaper_manager.h

Index: chrome/browser/chromeos/login/wallpaper_manager.h
diff --git a/chrome/browser/chromeos/login/wallpaper_manager.h b/chrome/browser/chromeos/login/wallpaper_manager.h
index 378fdaa15c46ee5de79555c7597c014ed0a4c1e3..bcaeccb40ff3d2d6917041ead7b39f8e6c08791e 100644
--- a/chrome/browser/chromeos/login/wallpaper_manager.h
+++ b/chrome/browser/chromeos/login/wallpaper_manager.h
@@ -165,16 +165,13 @@ class WallpaperManager: public system::TimezoneSettings::Observer,
   // 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;