Tame the proliferation of UserContext constructors

chrome/browser/chromeos/chrome_browser_main_chromeos.cc

Index: chrome/browser/chromeos/chrome_browser_main_chromeos.cc
diff --git a/chrome/browser/chromeos/chrome_browser_main_chromeos.cc b/chrome/browser/chromeos/chrome_browser_main_chromeos.cc
index a72b44deeec813a4cfac3347eae1f8101f363a92..45769d88ca8538d01de3c3385ec4b90bf6b45964 100644
--- a/chrome/browser/chromeos/chrome_browser_main_chromeos.cc
+++ b/chrome/browser/chromeos/chrome_browser_main_chromeos.cc
@@ -140,9 +140,10 @@ class StubLogin : public LoginStatusConsumer,
   StubLogin(std::string username, std::string password)
       : profile_prepared_(false) {
     authenticator_ = LoginUtils::Get()->CreateAuthenticator(this);
-    authenticator_.get()->AuthenticateToLogin(
-        ProfileHelper::GetSigninProfile(),
-        UserContext(username, password, std::string() /* auth_code */));
+    UserContext user_context(username);
+    user_context.SetPassword(password);
+    authenticator_.get()->AuthenticateToLogin(ProfileHelper::GetSigninProfile(),
+                                              user_context);
   }
 
   virtual ~StubLogin() {