Files.app: Add private API to check if PiexLoader is enabled or not.

third_party/closure_compiler/externs/file_manager_private.js

 // 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.
 
 /** @fileoverview Externs generated from namespace: fileManagerPrivate */
 
 /**
  * @typedef {{
  *   taskId: string,
  *   title: string,
@@ skipping 556 matching lines @@
 /**
  * Sets a tag on a file or a directory. Only Drive files are supported.
  * @param {string} entryURL
  * @param {string} visibility 'private' or 'public'
  * @param {string} key
  * @param {string} value
  * @param {function()} callback
  */
 chrome.fileManagerPrivate.setEntryTag = function(entryURL, visibility, key, value, callback) {};
 
+/**
+ * Gets a flag indicating whether PiexLoader is enabled.
+ * @param {function(boolean)} callback
+ */
+chrome.fileManagerPrivate.isPiexLoaderEnabled = function(callback) {};
+
 /** @type {!ChromeEvent} */
 chrome.fileManagerPrivate.onMountCompleted;
 
 /** @type {!ChromeEvent} */
 chrome.fileManagerPrivate.onFileTransfersUpdated;
 
 /** @type {!ChromeEvent} */
 chrome.fileManagerPrivate.onCopyProgress;
 
 /** @type {!ChromeEvent} */
 chrome.fileManagerPrivate.onDirectoryChanged;
 
 /** @type {!ChromeEvent} */
 chrome.fileManagerPrivate.onPreferencesChanged;
 
 /** @type {!ChromeEvent} */
 chrome.fileManagerPrivate.onDriveConnectionStatusChanged;
 
 /** @type {!ChromeEvent} */
 chrome.fileManagerPrivate.onDeviceChanged;
 
 /** @type {!ChromeEvent} */
 chrome.fileManagerPrivate.onDriveSyncError;