mandoline filesystem: Save cookie data to the mojo:filesystem.

components/filesystem/public/interfaces/file_system.mojom

 // Copyright 2015 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.
 
 module filesystem;
 
 import "components/filesystem/public/interfaces/directory.mojom";
 import "components/filesystem/public/interfaces/types.mojom";
 
+// Callback interface for FileSystem. When we call OpenFileSystem, we supply a
+// client to receive and handle the shutdown signal. Just because the shell has
+// closed the application connection to the FileSystem doesn't mean that we
+// should immediately kill all connections to our clients. We notify them that
+// we are shutting down so that they can flush any data and cleanly shutdown.
+//
+// Actual connection lifetime is controlled by the lifetime of the |directory|
+// object.
+interface FileSystemClient {
+  OnFileSystemShutdown();
+};
+
 interface FileSystem {
   // Opens the root directory for the file system with the given name; null
   // yields the default file system, if any.
-  OpenFileSystem(string? file_system, Directory& directory) => (FileError error);
+  OpenFileSystem(string? file_system, Directory& directory,
+                 FileSystemClient client) => (FileError error);
 };