[sync] Force re-auth during sync setup if Oauth2 token is unavailable

chrome/browser/ui/sync/one_click_signin_helper.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/sync/one_click_signin_helper.h"
 
 #include <algorithm>
 #include <functional>
 #include <utility>
 #include <vector>
@@ skipping 1245 matching lines @@
                           one_click_signin::HISTOGRAM_ACCEPTED);
       } else {
         LogHistogramValue(source_, one_click_signin::HISTOGRAM_ACCEPTED);
         LogHistogramValue(source_, one_click_signin::HISTOGRAM_WITH_DEFAULTS);
       }
 
       // - If sign in was initiated from the NTP or the hotdog menu, sync with
       //   default settings.
       // - If sign in was initiated from the settings page for first time sync
       //   set up, show the advanced sync settings dialog.
-      // - If sign in was initiated from the settings page due to a re-auth,
-      //   simply navigate back to the settings page.
+      // - If sign in was initiated from the settings page due to a re-auth when
+      //   sync was already setup, simply navigate back to the settings page.
+      ProfileSyncService* sync_service =
+          ProfileSyncServiceFactory::GetForProfile(profile);
       OneClickSigninSyncStarter::StartSyncMode start_mode =
           source_ == signin::SOURCE_SETTINGS ?
-              SigninGlobalError::GetForProfile(profile)->HasMenuItem() ?
+              (SigninGlobalError::GetForProfile(profile)->HasMenuItem() &&
+               sync_service && sync_service->HasSyncSetupCompleted()) ?
                   OneClickSigninSyncStarter::SHOW_SETTINGS_WITHOUT_CONFIGURE :
                   OneClickSigninSyncStarter::CONFIGURE_SYNC_FIRST :
               OneClickSigninSyncStarter::SYNC_WITH_DEFAULT_SETTINGS;
 
       std::string last_email =
           profile->GetPrefs()->GetString(prefs::kGoogleServicesLastUsername);
 
       if (!last_email.empty() && !gaia::AreEmailsSame(last_email, email_)) {
         // If the new email address is different from the email address that
         // just signed in, show a confirmation dialog.
@@ skipping 115 matching lines @@
     // If the web contents is showing a blank page and not about to be closed,
     // redirect to the NTP or apps page.
     if (signin::IsContinueUrlForWebBasedSigninFlow(current_url) &&
         !signin::IsAutoCloseEnabledInURL(original_continue_url_)) {
       RedirectToNtpOrAppsPage(
           web_contents(),
           signin::GetSourceForPromoURL(original_continue_url_));
     }
   }
 }