This CL replaces e-mail with AccountId in easy signin code.

chrome/browser/ui/webui/chromeos/login/signin_screen_handler.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/webui/chromeos/login/signin_screen_handler.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "ash/shell.h"
@@ skipping 278 matching lines @@
     keyboard->RemoveObserver(this);
   weak_factory_.InvalidateWeakPtrs();
   if (delegate_)
     delegate_->SetWebUIHandler(nullptr);
   network_state_informer_->RemoveObserver(this);
   if (max_mode_delegate_) {
     max_mode_delegate_->RemoveObserver(this);
     max_mode_delegate_.reset(nullptr);
   }
   proximity_auth::ScreenlockBridge::Get()->SetLockHandler(nullptr);
-  proximity_auth::ScreenlockBridge::Get()->SetFocusedUser("");
+  proximity_auth::ScreenlockBridge::Get()->SetFocusedUser(EmptyAccountId());
 }
 
 // static
 std::string SigninScreenHandler::GetUserLRUInputMethod(
     const std::string& username) {
   PrefService* const local_state = g_browser_process->local_state();
   const base::DictionaryValue* users_lru_input_methods =
       local_state->GetDictionary(prefs::kUsersLRUInputMethod);
 
   if (!users_lru_input_methods) {
@@ skipping 924 matching lines @@
     ScreenLocker::default_screen_locker()->UnlockOnLoginSuccess();
 }
 
 void SigninScreenHandler::HandleShowLoadingTimeoutError() {
   UpdateState(NetworkError::ERROR_REASON_LOADING_TIMEOUT);
 }
 
 void SigninScreenHandler::HandleFocusPod(const AccountId& account_id) {
   SetUserInputMethod(account_id.GetUserEmail(), ime_state_.get());
   WallpaperManager::Get()->SetUserWallpaperDelayed(account_id.GetUserEmail());
-  proximity_auth::ScreenlockBridge::Get()->SetFocusedUser(
-      account_id.GetUserEmail());
+  proximity_auth::ScreenlockBridge::Get()->SetFocusedUser(account_id);
   if (delegate_)
     delegate_->CheckUserStatus(account_id);
   if (!test_focus_pod_callback_.is_null())
     test_focus_pod_callback_.Run();
 
   bool use_24hour_clock = false;
   if (user_manager::UserManager::Get()->GetKnownUserBooleanPref(
           account_id, prefs::kUse24HourClock, &use_24hour_clock)) {
     g_browser_process->platform_part()
         ->GetSystemClock()
@@ skipping 155 matching lines @@
   return gaia_screen_handler_->frame_error();
 }
 
 void SigninScreenHandler::OnCapsLockChanged(bool enabled) {
   caps_lock_enabled_ = enabled;
   if (page_is_ready())
     CallJS("login.AccountPickerScreen.setCapsLockState", caps_lock_enabled_);
 }
 
 }  // namespace chromeos