Stop foreground depending on background in gyp v2

ui/file_manager/externs/background/drive_sync_handler.js

+// Copyright 2017 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.
+
+/**
+ * Handler of the background page for the drive sync events.
+ * @constructor
+ * @extends {cr.EventTarget}
+ * @struct
+ */
+function DriveSyncHandler() {}
+
+DriveSyncHandler.prototype = /** @struct */ {
+  /**
+   * @return {boolean} Whether the handler is having syncing items or not.
+   */
+  get syncing() {}
+};
+
+/**
+ * Returns whether the drive sync is currently suppressed or not.
+ * @return {boolean}
+ */
+DriveSyncHandler.prototype.isSyncSuppressed = function() {};
+
+/**
+ * Shows the notification saying that the drive sync is disabled on cellular
+ * network.
+ */
+DriveSyncHandler.prototype.showDisabledMobileSyncNotification = function() {};