Resolve new GAIA flow's infinite loop.

chrome/browser/chromeos/login/existing_user_controller.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/chromeos/login/existing_user_controller.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 675 matching lines @@
   offline_failed_ = false;
 
   if (g_browser_process->platform_part()
           ->browser_policy_connector_chromeos()
           ->IsEnterpriseManaged()) {
     ShowError(IDS_ENTERPRISE_LOGIN_ERROR_WHITELIST, email);
   } else {
     ShowError(IDS_LOGIN_ERROR_WHITELIST, email);
   }
 
-  login_display_->ShowSigninUI(email);
+  if (StartupUtils::IsWebviewSigninEnabled())
+    login_display_->ShowSigninUI("");
+  else
+    login_display_->ShowSigninUI(email);
 
   if (auth_status_consumer_) {
     auth_status_consumer_->OnAuthFailure(
         AuthFailure(AuthFailure::WHITELIST_CHECK_FAILED));
   }
 
   display_email_.clear();
 }
 
 void ExistingUserController::PolicyLoadFailed() {
@@ skipping 484 matching lines @@
 
   // Setting a customized login user flow to perform additional initializations
   // for bootstrap after the user session is started.
   ChromeUserManager::Get()->SetUserFlow(user_context.GetUserID(),
                                         new BootstrapUserFlow(user_context));
 
   PerformLogin(user_context, LoginPerformer::AUTH_MODE_EXTENSION);
 }
 
 }  // namespace chromeos