We should use UserID object to identify users instead of username.

chrome/browser/profiles/profile_impl.cc

 // Copyright (c) 2012 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/profiles/profile_impl.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 759 matching lines @@
 Profile* ProfileImpl::GetOriginalProfile() {
   return this;
 }
 
 bool ProfileImpl::IsSupervised() {
   return !GetPrefs()->GetString(prefs::kSupervisedUserId).empty();
 }
 
 bool ProfileImpl::IsChild() {
 #if defined(ENABLE_SUPERVISED_USERS)
-  return GetPrefs()->GetString(prefs::kSupervisedUserId) ==
-      supervised_users::kChildAccountSUID;
+  return user_manager::UserID::FromUserEmail(GetPrefs()->GetString(prefs::kSupervisedUserId)) ==
+      supervised_users::GetChildAccountSUID();
 #else
   return false;
 #endif
 }
 
 bool ProfileImpl::IsLegacySupervised() {
   return IsSupervised() && !IsChild();
 }
 
 ExtensionSpecialStoragePolicy*
@@ skipping 360 matching lines @@
     default: {
       NOTREACHED();
       break;
     }
   }
   if (do_update_pref)
     GetPrefs()->SetString(prefs::kApplicationLocale, new_locale);
   if (via != APP_LOCALE_CHANGED_VIA_PUBLIC_SESSION_LOGIN)
     local_state->SetString(prefs::kApplicationLocale, new_locale);
 
-  if (user_manager::UserManager::Get()->GetOwnerEmail() ==
-      chromeos::ProfileHelper::Get()->GetUserByProfile(this)->email())
+  if (user_manager::UserManager::Get()->GetOwnerID() ==
+      chromeos::ProfileHelper::Get()->GetUserByProfile(this)->GetUserID())
     local_state->SetString(prefs::kOwnerLocale, new_locale);
 }
 
 void ProfileImpl::OnLogin() {
   if (locale_change_guard_ == NULL)
     locale_change_guard_.reset(new chromeos::LocaleChangeGuard(this));
   locale_change_guard_->OnLogin();
 }
 
 void ProfileImpl::InitChromeOSPreferences() {
@@ skipping 50 matching lines @@
   if (!home_page.is_valid())
     return GURL(chrome::kChromeUINewTabURL);
   return home_page;
 }
 
 void ProfileImpl::UpdateProfileSupervisedUserIdCache() {
   ProfileManager* profile_manager = g_browser_process->profile_manager();
   ProfileInfoCache& cache = profile_manager->GetProfileInfoCache();
   size_t index = cache.GetIndexOfProfileWithPath(GetPath());
   if (index != std::string::npos) {
-    std::string supervised_user_id =
-        GetPrefs()->GetString(prefs::kSupervisedUserId);
+    const user_manager::UserID supervised_user_id(
+        user_manager::UserID::FromUserEmail(GetPrefs()->GetString(prefs::kSupervisedUserId)));
     cache.SetSupervisedUserIdOfProfileAtIndex(index, supervised_user_id);
     ProfileMetrics::UpdateReportedProfilesStatistics(profile_manager);
   }
 }
 
 void ProfileImpl::UpdateProfileNameCache() {
   ProfileManager* profile_manager = g_browser_process->profile_manager();
   ProfileInfoCache& cache = profile_manager->GetProfileInfoCache();
   size_t index = cache.GetIndexOfProfileWithPath(GetPath());
   if (index != std::string::npos) {
@@ skipping 65 matching lines @@
 ProfileImpl::CreateDomainReliabilityMonitor(PrefService* local_state) {
   domain_reliability::DomainReliabilityService* service =
       domain_reliability::DomainReliabilityServiceFactory::GetInstance()->
           GetForBrowserContext(this);
   if (!service)
     return scoped_ptr<domain_reliability::DomainReliabilityMonitor>();
 
   return service->CreateMonitor(
       BrowserThread::GetMessageLoopProxyForThread(BrowserThread::IO));
 }