This CL replaces user_manager::UserID with AccountId.

chrome/browser/ui/ash/multi_user/multi_user_window_manager.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/multi_user/multi_user_window_manager.h"
 
 #include "base/logging.h"
 #include "chrome/browser/ui/ash/multi_user/multi_user_window_manager_stub.h"
 
 #if defined(OS_CHROMEOS)
 #include "ash/ash_switches.h"
 #include "ash/multi_profile_uma.h"
 #include "ash/session/session_state_delegate.h"
 #include "ash/shell.h"
 #include "ash/shell_delegate.h"
 #include "chrome/browser/ui/ash/multi_user/multi_user_window_manager_chromeos.h"
+#include "components/signin/core/account_id/account_id.h"
 #include "components/user_manager/user_info.h"
 #endif
 
 namespace {
 chrome::MultiUserWindowManager* g_instance = NULL;
 }  // namespace
 
 namespace chrome {
 
 // Caching the current multi profile mode to avoid expensive detection
@@ skipping 12 matching lines @@
   multi_user_mode_ = MULTI_PROFILE_MODE_OFF;
 #if defined(OS_CHROMEOS)
   ash::MultiProfileUMA::SessionMode mode =
       ash::MultiProfileUMA::SESSION_SINGLE_USER_MODE;
   if (!g_instance &&
       ash::Shell::GetInstance()->delegate()->IsMultiProfilesEnabled()) {
     MultiUserWindowManagerChromeOS* manager =
         new MultiUserWindowManagerChromeOS(ash::Shell::GetInstance()
                                                ->session_state_delegate()
                                                ->GetUserInfo(0)
-                                               ->GetUserID());
+                                               ->GetAccountId()
+                                               .GetUserEmail());
     g_instance = manager;
     manager->Init();
     multi_user_mode_ = MULTI_PROFILE_MODE_SEPARATED;
     mode = ash::MultiProfileUMA::SESSION_SEPARATE_DESKTOP_MODE;
   } else if (ash::Shell::GetInstance()->delegate()->IsMultiProfilesEnabled()) {
     // The side by side mode is using the Single user window manager since all
     // windows are unmanaged side by side.
     multi_user_mode_ = MULTI_PROFILE_MODE_MIXED;
     mode = ash::MultiProfileUMA::SESSION_SIDE_BY_SIDE_MODE;
   }
@@ skipping 36 matching lines @@
 void MultiUserWindowManager::SetInstanceForTest(
     MultiUserWindowManager* instance,
     MultiProfileMode mode) {
   if (g_instance)
     DeleteInstance();
   g_instance = instance;
   multi_user_mode_ = mode;
 }
 
 }  // namespace chrome