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

chrome/browser/ui/ash/launcher/multi_profile_app_window_launcher_controller.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 "chrome/browser/ui/ash/launcher/multi_profile_app_window_launcher_controller.h"
 
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_manager.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/host_desktop.h"
+#include "components/signin/core/account_id/account_id.h"
 #include "extensions/browser/app_window/app_window.h"
 #include "extensions/browser/app_window/native_app_window.h"
 #include "ui/aura/window.h"
 
 namespace {
 
 bool ControlsWindow(aura::Window* window) {
   return chrome::GetHostDesktopTypeForNativeWindow(window) ==
          chrome::HOST_DESKTOP_TYPE_ASH;
 }
@@ skipping 57 matching lines @@
   if (!ControlsWindow(app_window->GetNativeWindow()))
     return;
 
   app_window_list_.push_back(app_window);
   Profile* profile = Profile::FromBrowserContext(app_window->browser_context());
   // If the window got created for a non active user but the user allowed to
   // teleport to the current user's desktop, we teleport it now.
   if (!multi_user_util::IsProfileFromActiveUser(profile) &&
       UserHasAppOnActiveDesktop(app_window)) {
     chrome::MultiUserWindowManager::GetInstance()->ShowWindowForUser(
-        app_window->GetNativeWindow(), multi_user_util::GetCurrentUserId());
+        app_window->GetNativeWindow(), multi_user_util::GetCurrentAccountId());
   }
 }
 
 void MultiProfileAppWindowLauncherController::OnAppWindowShown(
     extensions::AppWindow* app_window,
     bool was_hidden) {
   if (!ControlsWindow(app_window->GetNativeWindow()))
     return;
 
   Profile* profile = Profile::FromBrowserContext(app_window->browser_context());
@@ skipping 40 matching lines @@
       std::find(app_window_list_.begin(), app_window_list_.end(), app_window);
   DCHECK(it != app_window_list_.end());
   app_window_list_.erase(it);
 }
 
 bool MultiProfileAppWindowLauncherController::UserHasAppOnActiveDesktop(
     extensions::AppWindow* app_window) {
   const std::string& app_id = app_window->extension_id();
   content::BrowserContext* app_context = app_window->browser_context();
   DCHECK(!app_context->IsOffTheRecord());
-  const std::string& current_user = multi_user_util::GetCurrentUserId();
+  const AccountId current_account_id = multi_user_util::GetCurrentAccountId();
   chrome::MultiUserWindowManager* manager =
       chrome::MultiUserWindowManager::GetInstance();
   for (AppWindowList::iterator it = app_window_list_.begin();
        it != app_window_list_.end();
        ++it) {
     extensions::AppWindow* other_window = *it;
     DCHECK(!other_window->browser_context()->IsOffTheRecord());
     if (manager->IsWindowOnDesktopOfUser(other_window->GetNativeWindow(),
-                                         current_user) &&
+                                         current_account_id) &&
         app_id == other_window->extension_id() &&
         app_context == other_window->browser_context()) {
       return true;
     }
   }
   return false;
 }