We should use UserID object to identify users instead of username.

chrome/browser/ui/ash/system_tray_delegate_chromeos.cc

 // Copyright 2013 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/ash/system_tray_delegate_chromeos.h"
 
 #include <algorithm>
 #include <set>
 #include <string>
 #include <vector>
@@ skipping 81 matching lines @@
 #include "chrome/common/url_constants.h"
 #include "chrome/grit/generated_resources.h"
 #include "chrome/grit/locale_settings.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
 #include "chromeos/dbus/session_manager_client.h"
 #include "chromeos/login/login_state.h"
 #include "chromeos/network/portal_detector/network_portal_detector.h"
 #include "components/google/core/browser/google_util.h"
 #include "components/policy/core/common/cloud/cloud_policy_store.h"
 #include "components/user_manager/user.h"
+#include "components/user_manager/user_id.h"
 #include "components/user_manager/user_manager.h"
 #include "components/user_manager/user_type.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/user_metrics.h"
 #include "content/public/browser/web_contents.h"
 #include "device/bluetooth/bluetooth_adapter.h"
 #include "device/bluetooth/bluetooth_adapter_factory.h"
 #include "device/bluetooth/bluetooth_device.h"
 #include "net/base/escape.h"
@@ skipping 477 matching lines @@
           .size()) {
     // Don't show dialog if any logged in user in multi-profiles session
     // dismissed it.
     bool show_intro = true;
     const user_manager::UserList logged_in_users =
         user_manager::UserManager::Get()->GetLoggedInUsers();
     for (user_manager::UserList::const_iterator it = logged_in_users.begin();
          it != logged_in_users.end();
          ++it) {
       show_intro &= !multi_user_util::GetProfileFromUserID(
-                         multi_user_util::GetUserIDFromEmail((*it)->email()))
+                         multi_user_util::GetUserIDFromEmail((*it)->GetUserID().GetUserEmail()))
                          ->GetPrefs()
                          ->GetBoolean(prefs::kMultiProfileNeverShowIntro);
       if (!show_intro)
         break;
     }
     if (show_intro) {
       base::Callback<void(bool)> on_accept =
           base::Bind(&OnAcceptMultiprofilesIntro);
       ShowMultiprofilesIntroDialog(on_accept);
     } else {
@@ skipping 221 matching lines @@
   SetProfile(ProfileManager::GetActiveUserProfile());
   GetSystemTrayNotifier()->NotifyUserUpdate();
 }
 
 bool SystemTrayDelegateChromeOS::IsSearchKeyMappedToCapsLock() {
   return search_key_mapped_to_ == input_method::kCapsLockKey;
 }
 
 ash::tray::UserAccountsDelegate*
 SystemTrayDelegateChromeOS::GetUserAccountsDelegate(
-    const std::string& user_id) {
+    const user_manager::UserID& user_id) {
   if (!accounts_delegates_.contains(user_id)) {
     const user_manager::User* user =
         user_manager::UserManager::Get()->FindUser(user_id);
     Profile* user_profile = ProfileHelper::Get()->GetProfileByUserUnsafe(user);
     CHECK(user_profile);
     accounts_delegates_.set(
         user_id,
         scoped_ptr<ash::tray::UserAccountsDelegate>(
             new UserAccountsDelegateChromeOS(user_profile)));
   }
@@ skipping 491 matching lines @@
     policy::CloudPolicyStore* store) {
   UpdateEnterpriseDomain();
 }
 
 void SystemTrayDelegateChromeOS::OnStoreError(policy::CloudPolicyStore* store) {
   UpdateEnterpriseDomain();
 }
 
 // Overridden from ash::SessionStateObserver
 void SystemTrayDelegateChromeOS::UserAddedToSession(
-    const std::string& user_id) {
+    const user_manager::UserID& user_id) {
   GetSystemTrayNotifier()->NotifyUserAddedToSession();
 }
 
 void SystemTrayDelegateChromeOS::ActiveUserChanged(
-    const std::string& /* user_id */) {
+    const user_manager::UserID& /* user_id */) {
   UpdateClockType();
 }
 
 // Overridden from chrome::BrowserListObserver.
 void SystemTrayDelegateChromeOS::OnBrowserRemoved(Browser* browser) {
   NotifyIfLastWindowClosed();
 }
 
 // Overridden from extensions::AppWindowRegistry::Observer.
 void SystemTrayDelegateChromeOS::OnAppWindowRemoved(
@@ skipping 56 matching lines @@
   LOG(WARNING) << "SystemTrayDelegateChromeOS::GetChildUserMessage call while "
                << "ENABLE_SUPERVISED_USERS undefined.";
   return base::string16();
 }
 
 ash::SystemTrayDelegate* CreateSystemTrayDelegate() {
   return new SystemTrayDelegateChromeOS();
 }
 
 }  // namespace chromeos