[SyncFS] Construct and destruct sync_worker in worker_task_runner

chrome/browser/sync_file_system/drive_backend/sync_worker.cc

Index: chrome/browser/sync_file_system/drive_backend/sync_worker.cc
diff --git a/chrome/browser/sync_file_system/drive_backend/sync_worker.cc b/chrome/browser/sync_file_system/drive_backend/sync_worker.cc
index c2b7f87f6c4845a891b87221d8f8b1b5d3f5d626..a8a183c8e031ca7a52734963751cdcbfdc664ccf 100644
--- a/chrome/browser/sync_file_system/drive_backend/sync_worker.cc
+++ b/chrome/browser/sync_file_system/drive_backend/sync_worker.cc
@@ -85,6 +85,7 @@ void QueryAppStatusOnUIThread(
 
 }  // namespace
 
+// static
 scoped_ptr<SyncWorker> SyncWorker::CreateOnWorker(
     const base::FilePath& base_dir,
     Observer* observer,
@@ -97,7 +98,6 @@ scoped_ptr<SyncWorker> SyncWorker::CreateOnWorker(
                      sync_engine_context.Pass(),
                      env_override));
   sync_worker->AddObserver(observer);
-  sync_worker->Initialize();
 
   return sync_worker.Pass();
 }
@@ -133,7 +133,6 @@ void SyncWorker::RegisterOrigin(
     return;
   }
 
-  // TODO(peria): Forward |callback| to UI thread.
   task_manager_->ScheduleSyncTask(
       FROM_HERE,
       task.PassAs<SyncTask>(),
@@ -144,7 +143,6 @@ void SyncWorker::RegisterOrigin(
 void SyncWorker::EnableOrigin(
     const GURL& origin,
     const SyncStatusCallback& callback) {
-  // TODO(peria): Forward |callback| to UI thread.
   task_manager_->ScheduleTask(
       FROM_HERE,
       base::Bind(&SyncWorker::DoEnableApp,
@@ -157,7 +155,6 @@ void SyncWorker::EnableOrigin(
 void SyncWorker::DisableOrigin(
     const GURL& origin,
     const SyncStatusCallback& callback) {
-  // TODO(peria): Forward |callback| to UI thread.
   task_manager_->ScheduleTask(
       FROM_HERE,
       base::Bind(&SyncWorker::DoDisableApp,
@@ -171,7 +168,6 @@ void SyncWorker::UninstallOrigin(
     const GURL& origin,
     RemoteFileSyncService::UninstallFlag flag,
     const SyncStatusCallback& callback) {
-  // TODO(peria): Forward |callback| to UI thread.
   task_manager_->ScheduleSyncTask(
       FROM_HERE,
       scoped_ptr<SyncTask>(
@@ -189,7 +185,8 @@ void SyncWorker::ProcessRemoteChange(
       SyncTaskManager::PRIORITY_MED,
       base::Bind(&SyncWorker::DidProcessRemoteChange,
                  weak_ptr_factory_.GetWeakPtr(),
-                 syncer, callback));
+                 syncer,
+                 callback));
 }
 
 void SyncWorker::SetRemoteChangeProcessor(
@@ -291,7 +288,8 @@ void SyncWorker::ApplyLocalChange(
       SyncTaskManager::PRIORITY_MED,
       base::Bind(&SyncWorker::DidApplyLocalChange,
                  weak_ptr_factory_.GetWeakPtr(),
-                 syncer, callback));
+                 syncer,
+                 callback));
 }
 
 void SyncWorker::MaybeScheduleNextTask() {