This CL replaces e-mail with AccountId in wallpaper manager code.

chrome/browser/ui/webui/chromeos/login/signin_screen_handler.h

Index: chrome/browser/ui/webui/chromeos/login/signin_screen_handler.h
diff --git a/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.h b/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.h
index 853fb5647ff13c7fb1d62cbbd6c1cbda7516cf26..7cdb0b38307a80695e3d76424a9c1c81ccfbdd18 100644
--- a/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.h
+++ b/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.h
@@ -160,8 +160,8 @@ class SigninScreenHandlerDelegate {
   // Cancels user adding.
   virtual void CancelUserAdding() = 0;
 
-  // Load wallpaper for given |username|.
-  virtual void LoadWallpaper(const std::string& username) = 0;
+  // Load wallpaper for given |account_id|.
+  virtual void LoadWallpaper(const AccountId& account_id) = 0;
 
   // Loads the default sign-in wallpaper.
   virtual void LoadSigninWallpaper() = 0;