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

chrome/browser/chromeos/drive/job_scheduler.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/chromeos/drive/job_scheduler.h"
 
 #include <algorithm>
 
 #include "base/files/file_util.h"
 #include "base/metrics/histogram.h"
 #include "base/prefs/pref_service.h"
 #include "base/rand_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/stringprintf.h"
 #include "base/thread_task_runner_handle.h"
 #include "chrome/browser/drive/event_logger.h"
 #include "chrome/common/pref_names.h"
+#include "components/user_manager/user_id.h"
 #include "content/public/browser/browser_thread.h"
 #include "google_apis/drive/drive_api_parser.h"
 
 using content::BrowserThread;
 
 namespace drive {
 
 namespace {
 
 // All jobs are retried at maximum of kMaxRetryCount when they fail due to
@@ skipping 667 matching lines @@
   params.progress_callback = base::Bind(&JobScheduler::UpdateProgress,
                                         weak_ptr_factory_.GetWeakPtr(),
                                         new_job->job_info.job_id);
   new_job->task = base::Bind(&RunUploadExistingFile, uploader_.get(), params);
   new_job->abort_callback = CreateErrorRunCallback(callback);
   StartJob(new_job);
 }
 
 void JobScheduler::AddPermission(
     const std::string& resource_id,
-    const std::string& email,
+    const user_manager::UserID& user_id,
     google_apis::drive::PermissionRole role,
     const google_apis::EntryActionCallback& callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   DCHECK(!callback.is_null());
 
   JobEntry* new_job = CreateNewJob(TYPE_ADD_PERMISSION);
   new_job->task = base::Bind(&DriveServiceInterface::AddPermission,
                              base::Unretained(drive_service_),
                              resource_id,
-                             email,
+                             user_id,
                              role,
                              base::Bind(&JobScheduler::OnEntryActionJobDone,
                                         weak_ptr_factory_.GetWeakPtr(),
                                         new_job->job_info.job_id,
                                         callback));
   new_job->abort_callback = callback;
   StartJob(new_job);
 }
 
 JobScheduler::JobEntry* JobScheduler::CreateNewJob(JobType type) {
@@ skipping 460 matching lines @@
     case FILE_QUEUE:
       return "FILE_QUEUE";
     case NUM_QUEUES:
       break;  // This value is just a sentinel. Should never be used.
   }
   NOTREACHED();
   return "";
 }
 
 }  // namespace drive