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

chrome/browser/chromeos/policy/browser_policy_connector_chromeos.h

 // 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_POLICY_BROWSER_POLICY_CONNECTOR_CHROMEOS_H_
 #define CHROME_BROWSER_CHROMEOS_POLICY_BROWSER_POLICY_CONNECTOR_CHROMEOS_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "chrome/browser/chromeos/policy/device_cloud_policy_manager_chromeos.h"
 #include "chrome/browser/policy/chrome_browser_policy_connector.h"
 #include "components/policy/core/common/cloud/cloud_policy_constants.h"
 
 class PrefRegistrySimple;
 class PrefService;
 
 namespace net {
 class URLRequestContextGetter;
 }
 
+namespace user_manager {
+class UserID;
+}
+
 namespace policy {
 
 class AffiliatedCloudPolicyInvalidator;
 class AffiliatedInvalidationServiceProvider;
 class AffiliatedRemoteCommandsInvalidator;
 class ConsumerManagementService;
 class DeviceCloudPolicyInitializer;
 class DeviceLocalAccountPolicyService;
 class DeviceManagementService;
 struct EnrollmentConfig;
@@ skipping 37 matching lines @@
   // stored in the lockbox, or DEVICE_MODE_CONSUMER if the lockbox has been
   // locked empty, or DEVICE_MODE_UNKNOWN if the device has not been owned yet.
   // For other OSes the function will always return DEVICE_MODE_CONSUMER.
   DeviceMode GetDeviceMode();
 
   // Get the enrollment configuration for the device as decided by various
   // factors. See DeviceCloudPolicyInitializer::GetPrescribedEnrollmentConfig()
   // for details.
   EnrollmentConfig GetPrescribedEnrollmentConfig() const;
 
-  // Works out the user affiliation by checking the given |user_name| against
+  // Works out the user affiliation by checking the given |user_id| against
   // the installation attributes.
-  UserAffiliation GetUserAffiliation(const std::string& user_name);
+  UserAffiliation GetUserAffiliation(const user_manager::UserID& user_id);
 
   DeviceCloudPolicyManagerChromeOS* GetDeviceCloudPolicyManager() {
     return device_cloud_policy_manager_;
   }
 
   DeviceCloudPolicyInitializer* GetDeviceCloudPolicyInitializer() {
     return device_cloud_policy_initializer_.get();
   }
 
   DeviceLocalAccountPolicyService* GetDeviceLocalAccountPolicyService() {
@@ skipping 84 matching lines @@
   scoped_ptr<NetworkConfigurationUpdater> network_configuration_updater_;
 
   base::WeakPtrFactory<BrowserPolicyConnectorChromeOS> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserPolicyConnectorChromeOS);
 };
 
 }  // namespace policy
 
 #endif  // CHROME_BROWSER_CHROMEOS_POLICY_BROWSER_POLICY_CONNECTOR_CHROMEOS_H_