[SyncFS] Construct and destruct sync_worker in worker_task_runner

chrome/browser/sync_file_system/drive_backend/sync_worker.h

Index: chrome/browser/sync_file_system/drive_backend/sync_worker.h
diff --git a/chrome/browser/sync_file_system/drive_backend/sync_worker.h b/chrome/browser/sync_file_system/drive_backend/sync_worker.h
index 36742c77a6291d561df0cec7dc0d442ffad7ca4a..1cb7264bc5455a7a2664257a2a4ec8b75d75c814 100644
--- a/chrome/browser/sync_file_system/drive_backend/sync_worker.h
+++ b/chrome/browser/sync_file_system/drive_backend/sync_worker.h
@@ -49,7 +49,8 @@ class RemoteToLocalSyncer;
 class SyncEngineContext;
 class SyncEngineInitializer;
 
-class SyncWorker : public SyncTaskManager::Client {
+class SyncWorker : public SyncTaskManager::Client,
+                   public base::SupportsWeakPtr<SyncWorker> {

[tzik, 2014/05/26 06:50:21]

please revert this.

[peria, 2014/05/26 07:55:09]

Done.

  public:
   enum AppStatus {
     APP_STATUS_ENABLED,
@@ -61,6 +62,8 @@ class SyncWorker : public SyncTaskManager::Client {
 
   class Observer {
    public:
+    virtual ~Observer() {}

[tzik, 2014/05/26 06:50:21]

Not need to public?

[peria, 2014/05/26 07:55:09]

Done.

+
     virtual void OnPendingFileListUpdated(int item_count) = 0;
     virtual void OnFileStatusChanged(const fileapi::FileSystemURL& url,
                                      SyncFileStatus file_status,
@@ -68,9 +71,6 @@ class SyncWorker : public SyncTaskManager::Client {
                                      SyncDirection direction) = 0;
     virtual void UpdateServiceState(RemoteServiceState state,
                                     const std::string& description) = 0;
-
-   protected:
-    virtual ~Observer() {}
   };
 
   static scoped_ptr<SyncWorker> CreateOnWorker(
@@ -195,7 +195,6 @@ class SyncWorker : public SyncTaskManager::Client {
   scoped_ptr<SyncEngineContext> context_;
   ObserverList<Observer> observers_;
 
-  base::WeakPtrFactory<SyncWorker> weak_ptr_factory_;
   DISALLOW_COPY_AND_ASSIGN(SyncWorker);
 };