Fix closure compiling error of file manager.

third_party/closure_compiler/externs/file_manager_private.js

Index: third_party/closure_compiler/externs/file_manager_private.js
diff --git a/third_party/closure_compiler/externs/file_manager_private.js b/third_party/closure_compiler/externs/file_manager_private.js
index d1736ca00eccc345529f9f04e027583ee241978e..761dc6cc99ddbb49217ef4f197c14692f19ad534 100644
--- a/third_party/closure_compiler/externs/file_manager_private.js
+++ b/third_party/closure_compiler/externs/file_manager_private.js
@@ -201,6 +201,16 @@ var DriveConnectionState;
 var DeviceEvent;
 
 /**
+ * @typedef {{
+ *   extensionId: string,
+ *   name: string,
+ *   canConfigure: boolean,
+ *   canAdd: boolean
+ * }}
+ */
+var ProvidingExtension;
+
+/**
  * @const
  */
 chrome.fileManagerPrivate = {};
@@ -580,6 +590,30 @@ chrome.fileManagerPrivate.setEntryTag = function(entryURL, visibility, key, valu
  */
 chrome.fileManagerPrivate.isPiexLoaderEnabled = function(callback) {};
 
+/**
+ * Returns list of available providing extensions.
+ * @param {function(!Array<!ProvidingExtension>)} callback
+ */
+chrome.fileManagerPrivate.getProvidingExtensions = function(callback) {};
+
+/**
+ * Requests adding a new provided file system. If not possible, then an error
+ * via chrome.runtime.lastError is returned.
+ * @param {string} extensionId
+ * @param {function()} callback
+ */
+chrome.fileManagerPrivate.addProvidedFileSystem =
+    function(extensionId, callback) {};
+
+/**
+ * Requests configuring an existing file system. If not possible, then returns
+ * an error via chrome.runtime.lastError.
+ * @param {string} volumeId
+ * @param {function()} callback
+ */
+chrome.fileManagerPrivate.configureProvidedFileSystem =
+    function(volumeId, callback) {};
+
 /** @type {!ChromeEvent} */
 chrome.fileManagerPrivate.onMountCompleted;