[SyncFS] Construct and destruct sync_worker in worker_task_runner

chrome/browser/sync_file_system/drive_backend/sync_engine.cc

 // Copyright 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/sync_file_system/drive_backend/sync_engine.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/metrics/histogram.h"
@@ skipping 187 matching lines @@
   factories->insert(
       extensions::ExtensionsBrowserClient::Get()->GetExtensionSystemFactory());
 }
 
 SyncEngine::~SyncEngine() {
   net::NetworkChangeNotifier::RemoveNetworkChangeObserver(this);
   GetDriveService()->RemoveObserver(this);
   if (notification_manager_)
     notification_manager_->RemoveObserver(this);
 
-  // TODO(tzik): Destroy |sync_worker_| and |worker_observer_| on the worker.
+  WorkerObserver* worker_observer = worker_observer_.release();
+  if (!worker_task_runner_->DeleteSoon(FROM_HERE, worker_observer))
+    delete worker_observer;
+
+  SyncWorker* sync_worker = sync_worker_.release();
+  if (!worker_task_runner_->DeleteSoon(FROM_HERE, sync_worker))
+    delete sync_worker;
 }
 
 void SyncEngine::Initialize(const base::FilePath& base_dir,
                             base::SequencedTaskRunner* file_task_runner,
                             leveldb::Env* env_override) {
   // DriveServiceWrapper and DriveServiceOnWorker relay communications
   // between DriveService and syncers in SyncWorker.
   scoped_ptr<drive::DriveServiceInterface>
       drive_service_on_worker(
           new DriveServiceOnWorker(drive_service_wrapper_->AsWeakPtr(),
@@ skipping 13 matching lines @@
                                 file_task_runner));
 
   worker_observer_.reset(
       new WorkerObserver(base::MessageLoopProxy::current(),
                          weak_ptr_factory_.GetWeakPtr()));
 
   base::WeakPtr<ExtensionServiceInterface> extension_service_weak_ptr;
   if (extension_service_)
     extension_service_weak_ptr = extension_service_->AsWeakPtr();
 
-  // TODO(peria): Use PostTask on |worker_task_runner_| to call this function.
-  sync_worker_ = SyncWorker::CreateOnWorker(
+  sync_worker_.reset(new SyncWorker(
       base_dir,
-      worker_observer_.get(),
       extension_service_weak_ptr,
       sync_engine_context.Pass(),
-      env_override);
+      env_override));
+  sync_worker_->AddObserver(worker_observer_.get());
+  worker_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&SyncWorker::Initialize,
+                 base::Unretained(sync_worker_.get())));
 
   if (notification_manager_)
     notification_manager_->AddObserver(this);
   GetDriveService()->AddObserver(this);
   net::NetworkChangeNotifier::AddNetworkChangeObserver(this);
 }
 
 void SyncEngine::AddServiceObserver(SyncServiceObserver* observer) {
   service_observers_.AddObserver(observer);
 }
@@ skipping 281 matching lines @@
         tracker.tracker_kind() == TRACKER_KIND_APP_ROOT;
     if (is_app_enabled && !is_app_root_tracker_enabled)
       EnableOrigin(origin, base::Bind(&EmptyStatusCallback));
     else if (!is_app_enabled && is_app_root_tracker_enabled)
       DisableOrigin(origin, base::Bind(&EmptyStatusCallback));
   }
 }
 
 }  // namespace drive_backend
 }  // namespace sync_file_system