[fsp] Add notifications in case of slow operations.

chrome/browser/chromeos/file_system_provider/notification_manager_interface.h

+// 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_CHROMEOS_FILE_SYSTEM_PROVIDER_NOTIFICATION_MANAGER_INTERFACE_H_
+#define CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_NOTIFICATION_MANAGER_INTERFACE_H_
+
+#include "base/callback.h"
+
+namespace chromeos {
+namespace file_system_provider {
+
+// Handles notifications related to provided the file system.
+class NotificationManagerInterface {
+ public:
+  // Result of a notification.
+  enum NotificationResult { ABORT, CONTINUE };
+
+  // Callback for handling result of a notification.
+  typedef base::Callback<void(NotificationResult)> NotificationCallback;
+
+  NotificationManagerInterface() {}
+  virtual ~NotificationManagerInterface() {}
+
+  // Shows a notification about the request being unresponsive. The |callback|
+  // is called when the notification is closed.
+  virtual void ShowUnresponsiveNotification(
+      int id,
+      const NotificationCallback& callback) = 0;
+
+  // Hides a notification previously shown with |id|.
+  virtual void HideUnresponsiveNotification(int id) = 0;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(NotificationManagerInterface);
+};
+
+}  // namespace file_system_provider
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_NOTIFICATION_MANAGER_INTERFACE_H_