[NOCOMMIT] Make DriveService{Wrapper|Messenger} class

chrome/browser/sync_file_system/drive_backend/drive_service_wrapper.h

Index: chrome/browser/sync_file_system/drive_backend/drive_service_wrapper.h
diff --git a/chrome/browser/sync_file_system/drive_backend/drive_service_wrapper.h b/chrome/browser/sync_file_system/drive_backend/drive_service_wrapper.h
new file mode 100644
index 0000000000000000000000000000000000000000..b40cf259e679bb0c6ae920dbb1ae8284ba82c584
--- /dev/null
+++ b/chrome/browser/sync_file_system/drive_backend/drive_service_wrapper.h
@@ -0,0 +1,30 @@
+// Copyright 2014 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.
+
+#ifndef CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_DRIVE_SERVICE_WRAPPER_H_
+#define CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_DRIVE_SERVICE_WRAPPER_H_
+
+#include "base/memory/weak_ptr.h"
+#include "chrome/browser/drive/drive_service_interface.h"
+
+namespace sync_file_system {
+namespace drive_backend {
+
+// This class is a partial wrapper of drive::DriveServiceInterface class,
+// and supports weak pointer.
+class DriveServiceWrapper : public base::SupportsWeakPtr<DriveServiceWrapper> {
+ public:
+  DriveServiceWrapper(drive::DriveServiceInterface* drive_service);
+  ~DriveServiceWrapper();
+
+  drive::DriveServiceInterface* GetDriveService();
+
+ private:
+  drive::DriveServiceInterface* drive_service_;
+};
+
+}  // namespace drive_backend
+}  // namespace sync_file_system
+
+#endif  // CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_DRIVE_SERVICE_WRAPPER_H_