This CL replaces std::string user_id in ash/* with AccountId.

chrome/browser/notifications/message_center_notifications_unittest.cc

 // 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.
 
 #include "base/memory/scoped_ptr.h"
 #include "base/prefs/testing_pref_service.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/test/test_timeouts.h"
 #include "base/values.h"
 #include "chrome/browser/notifications/message_center_notification_manager.h"
@@ skipping 12 matching lines @@
 #include "ui/message_center/message_center_tray.h"
 #include "ui/message_center/message_center_types.h"
 #include "ui/message_center/notification_types.h"
 #include "ui/message_center/notifier_settings.h"
 
 #if defined(OS_CHROMEOS)
 #include "chrome/browser/ui/ash/multi_user/multi_user_notification_blocker_chromeos.h"
 #include "chrome/browser/ui/ash/multi_user/multi_user_util.h"
 #include "chrome/browser/ui/ash/multi_user/multi_user_window_manager.h"
 #include "chrome/browser/ui/ash/multi_user/multi_user_window_manager_chromeos.h"
+#include "components/signin/core/account_id/account_id.h"
 #endif
 
 namespace message_center {
 
 class MessageCenterNotificationManagerTest : public BrowserWithTestWindowTest {
  public:
   MessageCenterNotificationManagerTest() {}
 
  protected:
   void SetUp() override {
@@ skipping 64 matching lines @@
   notification_manager()->Add(GetANotification("test"), &profile);
   EXPECT_TRUE(message_center()->NotificationCount() == 1);
   ASSERT_TRUE(
       notification_manager()->Update(GetANotification("test"), &profile));
   EXPECT_TRUE(message_center()->NotificationCount() == 1);
 }
 
 #if defined(OS_CHROMEOS)
 TEST_F(MessageCenterNotificationManagerTest, MultiUserUpdates) {
   TestingProfile profile;
-  std::string active_user_id = multi_user_util::GetUserIDFromProfile(&profile);
+  const AccountId active_user_id(
+      multi_user_util::GetAccountIdFromProfile(&profile));
   chrome::MultiUserWindowManagerChromeOS* multi_user_window_manager =
       new chrome::MultiUserWindowManagerChromeOS(active_user_id);
   multi_user_window_manager->Init();
   chrome::MultiUserWindowManager::SetInstanceForTest(
       multi_user_window_manager,
       chrome::MultiUserWindowManager::MULTI_PROFILE_MODE_SEPARATED);
   scoped_ptr<MultiUserNotificationBlockerChromeOS> blocker(
       new MultiUserNotificationBlockerChromeOS(
           message_center::MessageCenter::Get(),
           active_user_id));
   EXPECT_EQ(0u, message_center()->NotificationCount());
   notification_manager()->Add(GetANotification("test"), &profile);
   EXPECT_EQ(1u, message_center()->NotificationCount());
   notification_manager()->Update(GetANotification("test"), &profile);
   EXPECT_EQ(1u, message_center()->NotificationCount());
   chrome::MultiUserWindowManager::DeleteInstance();
 }
 #endif
 
 }  // namespace message_center