Revert 221035 "Revert 219146 "[sync] Force re-auth during sync s..."

Restoring the change. Verified that this was not the cause of bug 278543.

> Revert 219146 "[sync] Force re-auth during sync setup if Oauth2 ..."
> 
> > [sync] Force re-auth during sync setup if Oauth2 token is unavailable
> > 
> > If an enterprise user disables sync via a dashboard clear, and goes on
> > to re-enable sync at a later time, set up can fail due to an expired or
> > missing Oauth2 token.
> > 
> > This patch updates SyncSetupHandler::OpenSyncSetup to first check if an
> > auth token is available for sync, and if not, force a re-auth.
> > 
> > R=atwilson
> > TBR=fgorski,rogerta
> > BUG=276650
> > TEST=Disable sync for an enterprise user, exit chrome, delete "Web
> > Data*" from the profile dir, restart chrome, and set up sync. Re-auth
> > must be forced in this case.
> > 
> > Review URL: https://chromiumcodereview.appspot.com/23005016
> 
> TBR=rsimha@chromium.org
> 
> Review URL: https://codereview.chromium.org/23759003

TBR=sail@chromium.org

Review URL: https://codereview.chromium.org/23458028

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@221740 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/signin/profile_oauth2_token_service.cc

@@ -155,6 +155,15 @@ void ProfileOAuth2TokenService::Observe(
       break;
     }
     case chrome::NOTIFICATION_TOKEN_LOADING_FINISHED:
+      // During startup, if the user is signed in and the OAuth2 refresh token
+      // is empty, flag it as an error by badging the menu. Otherwise, if the
+      // user goes on to set up sync, they will have to make two attempts:
+      // One to surface the OAuth2 error, and a second one after signing in.
+      // See crbug.com/276650.
+      if (!GetAccountId(profile_).empty() && GetRefreshToken().empty()) {
+        UpdateAuthError(GoogleServiceAuthError(
+            GoogleServiceAuthError::INVALID_GAIA_CREDENTIALS));
+      }
       FireRefreshTokensLoaded();
       break;
     default:

chrome/browser/ui/sync/one_click_signin_helper.cc

@@ -1251,11 +1251,14 @@ void OneClickSigninHelper::DidStopLoading(
       //   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;