[MD Settings][People] Force sign out only in the case of unrecoverable error

chrome/browser/ui/webui/options/sync_setup_handler.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/ui/webui/options/sync_setup_handler.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 629 matching lines @@
 #if defined(OS_CHROMEOS)
 // On ChromeOS, we need to sign out the user session to fix an auth error, so
 // the user goes through the real signin flow to generate a new auth token.
 void SyncSetupHandler::HandleAttemptUserExit(const base::ListValue* args) {
   chrome::AttemptUserExit();
 }
 #endif
 
 #if !defined(OS_CHROMEOS)
 void SyncSetupHandler::HandleStartSignin(const base::ListValue* args) {
-  // Should only be called if the user is not already signed in.
-  DCHECK(!SigninManagerFactory::GetForProfile(GetProfile())->IsAuthenticated());
+  // Should only be called if the user is not already signed in or has an auth
+  // error.
+  DCHECK(
+      !SigninManagerFactory::GetForProfile(GetProfile())->IsAuthenticated() ||
+      SigninErrorControllerFactory::GetForProfile(GetProfile())->HasError());
   bool creating_supervised_user = false;
   args->GetBoolean(0, &creating_supervised_user);
   OpenSyncSetup(creating_supervised_user);
 }
 
 void SyncSetupHandler::HandleStopSyncing(const base::ListValue* args) {
   if (GetSyncService())
     ProfileSyncService::SyncEvent(ProfileSyncService::STOP_FROM_OPTIONS);
 
   bool delete_profile = false;
@@ skipping 282 matching lines @@
                                          page, args);
 
   // Make sure the tab used for the Gaia sign in does not cover the settings
   // tab.
   FocusUI();
 }
 
 LoginUIService* SyncSetupHandler::GetLoginUIService() const {
   return LoginUIServiceFactory::GetForProfile(GetProfile());
 }