This CL replaces user_manager::UserID with AccountId.

chrome/browser/chromeos/login/lock/screen_locker.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/chromeos/login/lock/screen_locker.h"
 
 #include <string>
 #include <vector>
 
 #include "ash/ash_switches.h"
@@ skipping 179 matching lines @@
                                   IDS_LOGIN_ERROR_AUTHENTICATING,
                               HelpAppLauncher::HELP_CANT_ACCESS_ACCOUNT);
 
   if (auth_status_consumer_)
     auth_status_consumer_->OnAuthFailure(error);
 }
 
 void ScreenLocker::OnAuthSuccess(const UserContext& user_context) {
   incorrect_passwords_count_ = 0;
   if (authentication_start_time_.is_null()) {
-    if (!user_context.GetUserID().empty())
+    if (user_context.GetAccountId().is_valid())
       LOG(ERROR) << "Start time is not set at authentication success";
   } else {
     base::TimeDelta delta = base::Time::Now() - authentication_start_time_;
     VLOG(1) << "Authentication success: " << delta.InSecondsF() << " second(s)";
     UMA_HISTOGRAM_TIMES("ScreenLocker.AuthenticationSuccessTime", delta);
   }
 
   const user_manager::User* user =
-      user_manager::UserManager::Get()->FindUser(user_context.GetUserID());
+      user_manager::UserManager::Get()->FindUser(user_context.GetAccountId());
   if (user) {
     if (!user->is_active()) {
       saved_ime_state_ = NULL;
       user_manager::UserManager::Get()->SwitchActiveUser(
-          user_context.GetUserID());
+          user_context.GetAccountId());
     }
     UserSessionManager::GetInstance()->UpdateEasyUnlockKeys(user_context);
   } else {
     NOTREACHED() << "Logged in user not found.";
   }
 
   authentication_capture_.reset(new AuthenticationParametersCapture());
   authentication_capture_->user_context = user_context;
 
   // Add guard for case when something get broken in call chain to unlock
@@ skipping 18 matching lines @@
     auth_status_consumer_->OnAuthSuccess(authentication_capture_->user_context);
   }
   authentication_capture_.reset();
   weak_factory_.InvalidateWeakPtrs();
 
   VLOG(1) << "Hiding the lock screen.";
   chromeos::ScreenLocker::Hide();
 }
 
 void ScreenLocker::Authenticate(const UserContext& user_context) {
-  LOG_ASSERT(IsUserLoggedIn(user_context.GetUserID()))
+  LOG_ASSERT(IsUserLoggedIn(user_context.GetAccountId().GetUserEmail()))
       << "Invalid user trying to unlock.";
 
   authentication_start_time_ = base::Time::Now();
   delegate_->SetInputEnabled(false);
   delegate_->OnAuthenticate();
 
   // Special case: supervised users. Use special authenticator.
   if (const user_manager::User* user =
-          FindUnlockUser(user_context.GetUserID())) {
+          FindUnlockUser(user_context.GetAccountId().GetUserEmail())) {
     if (user->GetType() == user_manager::USER_TYPE_SUPERVISED) {
       UserContext updated_context = ChromeUserManager::Get()
                                         ->GetSupervisedUserManager()
                                         ->GetAuthentication()
                                         ->TransformKey(user_context);
       // TODO(antrim) : replace empty closure with explicit method.
       // http://crbug.com/351268
       BrowserThread::PostTask(
           BrowserThread::UI,
           FROM_HERE,
           base::Bind(&ExtendedAuthenticator::AuthenticateToCheck,
                      extended_authenticator_.get(),
                      updated_context,
                      base::Closure()));
       return;
     }
   }
 
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
       base::Bind(&ExtendedAuthenticator::AuthenticateToCheck,
                  extended_authenticator_.get(),
                  user_context,
                  base::Closure()));
 }
 
 const user_manager::User* ScreenLocker::FindUnlockUser(
     const std::string& user_id) {

[achuithb, 2015/10/28 23:11:45]

AccountId?

[Alexander Alekseev, 2015/10/29 02:00:40]

Sure. In another CL.

   const user_manager::User* unlock_user = NULL;
   for (user_manager::UserList::const_iterator it = users_.begin();
        it != users_.end();
        ++it) {
     if ((*it)->email() == user_id) {
       unlock_user = *it;
       break;
     }
   }
   return unlock_user;
@@ skipping 193 matching lines @@
 
   input_method::InputMethodManager::Get()
       ->GetActiveIMEState()
       ->EnableLockScreenLayouts();
 }
 
 content::WebUI* ScreenLocker::GetAssociatedWebUI() {
   return delegate_->GetAssociatedWebUI();
 }
 
 bool ScreenLocker::IsUserLoggedIn(const std::string& username) {

[achuithb, 2015/10/28 23:11:45]

AccountId instead?

[Alexander Alekseev, 2015/10/29 02:00:40]

In another CL.

   for (user_manager::UserList::const_iterator it = users_.begin();
        it != users_.end();
        ++it) {
     if ((*it)->email() == username)
       return true;
   }
   return false;
 }
 
 }  // namespace chromeos