[cros] Update wallpaper when displaying Gaia frame.

chrome/browser/chromeos/login/wallpaper_manager.cc

Index: chrome/browser/chromeos/login/wallpaper_manager.cc
diff --git a/chrome/browser/chromeos/login/wallpaper_manager.cc b/chrome/browser/chromeos/login/wallpaper_manager.cc
index 04f7c35485ecf5995e0dbcb1ec3e76b30fc017ee..a9da6122ede9cb1c422e50bad68be84401cd532f 100644
--- a/chrome/browser/chromeos/login/wallpaper_manager.cc
+++ b/chrome/browser/chromeos/login/wallpaper_manager.cc
@@ -681,6 +681,11 @@ void WallpaperManager::SetUserWallpaper(const std::string& email) {
   }
 }
 
+void WallpaperManager::SetSigninWallpaper() {
+  ash::Shell::GetInstance()->desktop_background_controller()->
+      SetDefaultWallpaper(kDefaultOOBEWallpaperIndex, false);
+}
+
 void WallpaperManager::SetWallpaperFromImageSkia(
     const gfx::ImageSkia& wallpaper,
     ash::WallpaperLayout layout) {
@@ -688,10 +693,6 @@ void WallpaperManager::SetWallpaperFromImageSkia(
       SetCustomWallpaper(wallpaper, layout);
 }
 
-void WallpaperManager::OnUserSelected(const std::string& email) {
-  SetUserWallpaper(email);
-}
-
 // WallpaperManager, private: --------------------------------------------------
 
 WallpaperManager::~WallpaperManager() {