ListAccounts will return the Gaia ID as well as the email of the account.

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 46 matching lines @@
   void Shutdown() override;
 
   // Determine what the reconcilor is currently doing.
   signin_metrics::AccountReconcilorState GetState();
 
  private:
   bool IsRegisteredWithTokenService() const {
     return registered_with_token_service_;
   }
 
-  const std::vector<std::pair<std::string, bool> >& GetGaiaAccountsForTesting()
-      const {
-    return gaia_accounts_;
-  }
-
   friend class AccountReconcilorTest;
   FRIEND_TEST_ALL_PREFIXES(AccountReconcilorTest, SigninManagerRegistration);
   FRIEND_TEST_ALL_PREFIXES(AccountReconcilorTest, Reauth);
   FRIEND_TEST_ALL_PREFIXES(AccountReconcilorTest, ProfileAlreadyConnected);
   FRIEND_TEST_ALL_PREFIXES(AccountReconcilorTest,
                            StartReconcileCookiesDisabled);
   FRIEND_TEST_ALL_PREFIXES(AccountReconcilorTest,
                            StartReconcileContentSettings);
   FRIEND_TEST_ALL_PREFIXES(AccountReconcilorTest,
                            StartReconcileContentSettingsGaiaUrl);
@@ skipping 51 matching lines @@
       const ContentSettingsPattern& primary_pattern,
       const ContentSettingsPattern& secondary_pattern,
       ContentSettingsType content_type,
       std::string resource_identifier) override;
 
   // Overriden from GaiaGookieManagerService::Observer.
   void OnAddAccountToCookieCompleted(
       const std::string& account_id,
       const GoogleServiceAuthError& error) override;
   void OnGaiaAccountsInCookieUpdated(
-        const std::vector<std::pair<std::string, bool> >& accounts,
+        const std::vector<gaia::ListedAccount>& accounts,
         const GoogleServiceAuthError& error) 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,
@@ skipping 22 matching lines @@
 
   // True iff this is the first time the reconcilor is executing.
   bool first_execution_;
 
   // True iff an error occured during the last attempt to reconcile.
   bool error_during_last_reconcile_;
 
   // Used during reconcile action.
   // These members are used to validate the gaia cookie.  |gaia_accounts_|
   // holds the state of google accounts in the gaia cookie.  Each element is
-  // a pair that holds the email address of the account and a boolean that
-  // indicates whether the account is valid or not.  The accounts in the vector
-  // are ordered the in same way as the gaia cookie.
-  std::vector<std::pair<std::string, bool> > gaia_accounts_;
+  // holds the email address, gaia id and validity as returned from GAIA.  The
+  // accounts in the vector are ordered the in same way as the gaia cookie.
+  std::vector<gaia::ListedAccount> gaia_accounts_;
 
   // Used during reconcile action.
   // These members are used to validate the tokens in OAuth2TokenService.
   std::string primary_account_;
   std::vector<std::string> chrome_accounts_;
   std::vector<std::string> add_to_cookie_;
   bool chrome_accounts_changed_;
 
   DISALLOW_COPY_AND_ASSIGN(AccountReconcilor);
 };
 
 #endif  // COMPONENTS_SIGNIN_CORE_BROWSER_ACCOUNT_RECONCILOR_H_