ChromeOS NetworkScreenHandler should not call CheckAndResolveLocale on UI thread.

chrome/browser/chromeos/login/session/user_session_manager.h

Index: chrome/browser/chromeos/login/session/user_session_manager.h
diff --git a/chrome/browser/chromeos/login/session/user_session_manager.h b/chrome/browser/chromeos/login/session/user_session_manager.h
index 8a27904a67be1a2a1f93fbe50de19af40f81b63a..da47925bd505915b3b7ce807e5a99e0a115f1a21 100644
--- a/chrome/browser/chromeos/login/session/user_session_manager.h
+++ b/chrome/browser/chromeos/login/session/user_session_manager.h
@@ -147,7 +147,7 @@ class UserSessionManager
   bool RespectLocalePreference(
       Profile* profile,
       const user_manager::User* user,
-      scoped_ptr<locale_util::SwitchLanguageCallback> callback) const;
+      const locale_util::SwitchLanguageCallback& callback) const;
 
   // Returns true if Easy unlock keys needs to be updated.
   bool NeedsToUpdateEasyUnlockKeys() const;