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

chrome/browser/ui/webui/signin_internals_ui.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/signin_internals_ui.h"
 
 #include "base/hash.h"
 #include "base/profiler/scoped_tracker.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/signin/about_signin_internals_factory.h"
@@ skipping 55 matching lines @@
         AboutSigninInternalsFactory::GetForProfile(profile);
     // TODO(vishwath): The UI would look better if we passed in a dict with some
     // reasonable defaults, so the about:signin-internals page doesn't look
     // empty in incognito mode. Alternatively, we could force about:signin to
     // open in non-incognito mode always (like about:settings for ex.).
     if (about_signin_internals) {
       web_ui()->CallJavascriptFunction(
           "chrome.signin.getSigninInfo.handleReply",
           *about_signin_internals->GetSigninStatus());
 
-      std::vector<std::pair<std::string, bool>> cookie_accounts;
+      std::vector<gaia::ListedAccount> cookie_accounts;
       GaiaCookieManagerService* cookie_manager_service =
           GaiaCookieManagerServiceFactory::GetForProfile(profile);
       if (cookie_manager_service->ListAccounts(&cookie_accounts)) {
         about_signin_internals->OnGaiaAccountsInCookieUpdated(
             cookie_accounts,
             GoogleServiceAuthError(GoogleServiceAuthError::NONE));
       }
 
       return true;
     }
@@ skipping 11 matching lines @@
 
   web_ui()->CallJavascriptFunction(
       "chrome.signin.onSigninInfoChanged.fire", *info);
 }
 
 void SignInInternalsUI::OnCookieAccountsFetched(
     const base::DictionaryValue* info) {
   web_ui()->CallJavascriptFunction(
       "chrome.signin.onCookieAccountsFetched.fire", *info);
 }