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

chrome/browser/ui/views/frame/system_menu_model_builder.cc

 // Copyright (c) 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/views/frame/system_menu_model_builder.h"
 
 #include "base/command_line.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/app/chrome_command_ids.h"
 #include "chrome/browser/ui/browser_commands.h"
 #include "chrome/browser/ui/host_desktop.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/browser/ui/toolbar/app_menu_model.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/grit/generated_resources.h"
 #include "ui/base/accelerators/accelerator.h"
 #include "ui/base/models/simple_menu_model.h"
 
 #if defined(OS_CHROMEOS)
 #include "ash/session/session_state_delegate.h"
 #include "ash/shell.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/browser_window.h"
+#include "components/signin/core/account_id/account_id.h"
 #include "components/user_manager/user_info.h"
 #include "ui/base/l10n/l10n_util.h"
 #endif
 
 namespace {
 
 // Given a |browser| that's an app or popup window, checks if it's hosting the
 // settings page.
 bool IsChromeSettingsAppOrPopupWindow(Browser* browser) {
   DCHECK(browser);
@@ skipping 126 matching lines @@
   ash::SessionStateDelegate* delegate =
       ash::Shell::GetInstance()->session_state_delegate();
   int logged_in_users = delegate->NumberOfLoggedInUsers();
   if (logged_in_users <= 1)
     return;
 
   // If this does not belong to a profile or there is no window, or the window
   // is not owned by anyone, we don't show the menu addition.
   chrome::MultiUserWindowManager* manager =
       chrome::MultiUserWindowManager::GetInstance();
-  const std::string user_id =
-      multi_user_util::GetUserIDFromProfile(browser()->profile());
+  const AccountId account_id =
+      multi_user_util::GetAccountIdFromProfile(browser()->profile());
   aura::Window* window = browser()->window()->GetNativeWindow();
-  if (user_id.empty() || !window || manager->GetWindowOwner(window).empty())
+  if (!account_id.is_valid() || !window ||
+      !manager->GetWindowOwner(window).is_valid())
     return;
 
   model->AddSeparator(ui::NORMAL_SEPARATOR);
   DCHECK(logged_in_users <= 3);
   for (int user_index = 1; user_index < logged_in_users; ++user_index) {
     const user_manager::UserInfo* user_info = delegate->GetUserInfo(user_index);
     model->AddItem(
         user_index == 1 ? IDC_VISIT_DESKTOP_OF_LRU_USER_2
                         : IDC_VISIT_DESKTOP_OF_LRU_USER_3,
         l10n_util::GetStringFUTF16(IDS_VISIT_DESKTOP_OF_LRU_USER,
                                    user_info->GetDisplayName(),
                                    base::ASCIIToUTF16(user_info->GetEmail())));
   }
 #endif
 }