GCMS has automatic checks for CheckExternalConnections. It will be

components/signin/core/browser/account_reconcilor.h

 // Copyright 2014 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.
 #ifndef COMPONENTS_SIGNIN_CORE_BROWSER_ACCOUNT_RECONCILOR_H_
 #define COMPONENTS_SIGNIN_CORE_BROWSER_ACCOUNT_RECONCILOR_H_
 
 #include <deque>
 #include <functional>
 #include <set>
 #include <string>
@@ skipping 143 matching lines @@
       std::string resource_identifier) override;
 
   // Overriden from GaiaAuthConsumer.
   void OnListAccountsSuccess(const std::string& data) override;
   void OnListAccountsFailure(const GoogleServiceAuthError& error) override;
 
   // Overriden from MergeSessionHelper::Observer.
   void OnAddAccountToCookieCompleted(
       const std::string& account_id,
       const GoogleServiceAuthError& error) override;
-  void GetCheckConnectionInfoCompleted(bool succeeded) override;
 
   // Overriden from OAuth2TokenService::Observer.
   void OnEndBatchChanges() override;
 
   // Overriden from SigninManagerBase::Observer.
   void GoogleSigninSucceeded(const std::string& account_id,
                              const std::string& username,
                              const std::string& password) override;
   void GoogleSignedOut(const std::string& account_id,
                        const std::string& username) override;
@@ skipping 43 matching lines @@
 
   std::deque<GetAccountsFromCookieCallback> get_gaia_accounts_callbacks_;
 
   scoped_ptr<SigninClient::CookieChangedSubscription>
       cookie_changed_subscription_;
 
   DISALLOW_COPY_AND_ASSIGN(AccountReconcilor);
 };
 
 #endif  // COMPONENTS_SIGNIN_CORE_BROWSER_ACCOUNT_RECONCILOR_H_