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

chrome/browser/ui/webui/options/browser_options_handler.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/ui/webui/options/browser_options_handler.h"
 
 #include <set>
 #include <string>
 #include <vector>
 
@@ skipping 529 matching lines @@
   values->SetString("hotwordManageAudioHistoryURL",
                     chrome::kManageAudioHistoryURL);
 
 #if defined(OS_CHROMEOS)
   Profile* profile = Profile::FromWebUI(web_ui());
   std::string username = profile->GetProfileUserName();
   if (username.empty()) {
     const user_manager::User* user =
         chromeos::ProfileHelper::Get()->GetUserByProfile(profile);
     if (user && (user->GetType() != user_manager::USER_TYPE_GUEST))
-      username = user->email();
+      username = user->GetUserID().GetUserEmail();
   }
   if (!username.empty())
     username = gaia::SanitizeEmail(gaia::CanonicalizeEmail(username));
 
   values->SetString("username", username);
 #endif
   // Pass along sync status early so it will be available during page init.
   values->Set("syncData", GetSyncStateDictionary().release());
 
   values->SetString("privacyLearnMoreURL", chrome::kPrivacyLearnMoreURL);
@@ skipping 463 matching lines @@
   Profile* profile = Profile::FromWebUI(web_ui());
   OnAccountPictureManagedChanged(
       policy::ProfilePolicyConnectorFactory::GetForBrowserContext(profile)
           ->policy_service()
           ->GetPolicies(policy::PolicyNamespace(policy::POLICY_DOMAIN_CHROME,
                                                 std::string()))
           .Get(policy::key::kUserAvatarImage));
 
   OnWallpaperManagedChanged(
       chromeos::WallpaperManager::Get()->IsPolicyControlled(
-          user_manager::UserManager::Get()->GetActiveUser()->email()));
+          user_manager::UserManager::Get()->GetActiveUser()->GetUserID()));
 
   policy::ConsumerManagementService* consumer_management =
       g_browser_process->platform_part()->browser_policy_connector_chromeos()->
           GetConsumerManagementService();
   if (consumer_management) {
     OnConsumerManagementStatusChanged();
     consumer_management->AddObserver(this);
   }
 #endif
 }
@@ skipping 391 matching lines @@
 void BrowserOptionsHandler::ThemesSetNative(const base::ListValue* args) {
   content::RecordAction(UserMetricsAction("Options_GtkThemeSet"));
   Profile* profile = Profile::FromWebUI(web_ui());
   ThemeServiceFactory::GetForProfile(profile)->UseSystemTheme();
 }
 #endif
 
 #if defined(OS_CHROMEOS)
 void BrowserOptionsHandler::UpdateAccountPicture() {
   std::string email =
-      user_manager::UserManager::Get()->GetLoggedInUser()->email();
+      user_manager::UserManager::Get()->GetLoggedInUser()->GetUserID().GetUserEmail();
   if (!email.empty()) {
     web_ui()->CallJavascriptFunction("BrowserOptions.updateAccountPicture");
     base::StringValue email_value(email);
     web_ui()->CallJavascriptFunction("BrowserOptions.updateAccountPicture",
                                      email_value);
   }
 }
 
 void BrowserOptionsHandler::OnAccountPictureManagedChanged(bool managed) {
   web_ui()->CallJavascriptFunction("BrowserOptions.setAccountPictureManaged",
@@ skipping 716 matching lines @@
 void BrowserOptionsHandler::OnPolicyUpdated(const policy::PolicyNamespace& ns,
                                             const policy::PolicyMap& previous,
                                             const policy::PolicyMap& current) {
   std::set<std::string> different_keys;
   current.GetDifferingKeys(previous, &different_keys);
   if (ContainsKey(different_keys, policy::key::kMetricsReportingEnabled))
     SetupMetricsReportingCheckbox();
 }
 
 }  // namespace options