[SyncFS] Construct and destruct sync_worker in worker_task_runner

chrome/browser/sync_file_system/drive_backend/sync_engine.cc

Index: chrome/browser/sync_file_system/drive_backend/sync_engine.cc
diff --git a/chrome/browser/sync_file_system/drive_backend/sync_engine.cc b/chrome/browser/sync_file_system/drive_backend/sync_engine.cc
index be3a51a18477c1f3ae973dd9d3b7ed15d643fffe..e1c79cd59d39c80c50b2ea5dff3b10694332a901 100644
--- a/chrome/browser/sync_file_system/drive_backend/sync_engine.cc
+++ b/chrome/browser/sync_file_system/drive_backend/sync_engine.cc
@@ -8,6 +8,7 @@
 
 #include "base/bind.h"
 #include "base/metrics/histogram.h"
+#include "base/run_loop.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "base/time/time.h"
 #include "base/values.h"
@@ -66,7 +67,6 @@ class SyncEngine::WorkerObserver : public SyncWorker::Observer {
                  base::WeakPtr<SyncEngine> sync_engine)
       : ui_task_runner_(ui_task_runner),
         sync_engine_(sync_engine) {}
-
   virtual ~WorkerObserver() {}
 
   virtual void OnPendingFileListUpdated(int item_count) OVERRIDE {
@@ -183,9 +183,12 @@ scoped_ptr<SyncEngine> SyncEngine::CreateForBrowserContext(
                      notification_manager,
                      extension_service,
                      signin_manager));
+  base::RunLoop run_loop;
   sync_engine->Initialize(GetSyncFileSystemDir(context->GetPath()),
                           file_task_runner.get(),
+                          run_loop.QuitClosure(),
                           NULL);
+  run_loop.Run();

[nhiroki, 2014/05/26 05:31:32]

Hmm... this can block the UI thread?

 
   return sync_engine.Pass();
 }
@@ -205,11 +208,17 @@ SyncEngine::~SyncEngine() {
   if (notification_manager_)
     notification_manager_->RemoveObserver(this);
 
-  // TODO(tzik): Destroy |sync_worker_| and |worker_observer_| on the worker.
+  worker_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(
+          &SyncWorker::DestructOnWorker,
+          base::Passed(&sync_worker_),
+          base::Passed(worker_observer_.PassAs<SyncWorker::Observer>())));
 }
 
 void SyncEngine::Initialize(const base::FilePath& base_dir,
                             base::SequencedTaskRunner* file_task_runner,
+                            const base::Closure& closure,
                             leveldb::Env* env_override) {
   // DriveServiceWrapper and DriveServiceOnWorker relay communications
   // between DriveService and syncers in SyncWorker.
@@ -239,18 +248,23 @@ void SyncEngine::Initialize(const base::FilePath& base_dir,
   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(
-      base_dir,
-      worker_observer_.get(),
-      extension_service_weak_ptr,
-      sync_engine_context.Pass(),
-      env_override);
-
   if (notification_manager_)
     notification_manager_->AddObserver(this);
   GetDriveService()->AddObserver(this);
   net::NetworkChangeNotifier::AddNetworkChangeObserver(this);

[nhiroki, 2014/05/26 05:22:44]

I haven't read sourcecode closely, but I guess these observers should be added
after a worker is created.

[peria, 2014/05/26 05:32:35]

Done.
Yes, those observers communicate with SyncWorker through SyncEngine!

+
+  PostTaskAndReplyWithResult(
+      worker_task_runner_,
+      FROM_HERE,
+      base::Bind(&SyncWorker::CreateOnWorker,
+                 base_dir,
+                 worker_observer_.get(),
+                 extension_service_weak_ptr,
+                 base::Passed(sync_engine_context.Pass()),
+                 env_override),
+      base::Bind(&SyncEngine::SetSyncWorker,
+                 weak_ptr_factory_.GetWeakPtr(),
+                 closure));
 }
 
 void SyncEngine::AddServiceObserver(SyncServiceObserver* observer) {
@@ -545,5 +559,11 @@ void SyncEngine::UpdateRegisteredApps() {
   }
 }
 
+void SyncEngine::SetSyncWorker(const base::Closure& closure,
+                               scoped_ptr<SyncWorker> sync_worker) {
+  sync_worker_ = sync_worker.Pass();
+  closure.Run();
+}
+
 }  // namespace drive_backend
 }  // namespace sync_file_system