[cleanup] Files.app: Fix the mis-styled JSdoc in function_sequence.js.

chrome/browser/resources/file_manager/js/metadata/function_sequence.js

 // Copyright (c) 2012 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.
 
 /**
  * @constructor
  * @class FunctionSequence to invoke steps in sequence
  *
  * @param {Array} steps                array of functions to invoke in sequence
  * @param {Object} logger              logger
- * @param {Function} [callback]        callback to invoke on success
- * @param {Function} [failureCallback] callback to invoke on failure
+ * @param {Function} callback          callback to invoke on success
+ * @param {Function} failureCallback   callback to invoke on failure
  */
 function FunctionSequence(name, steps, logger, callback, failureCallback) {
   // Private variables hidden in closure
   this.currentStepIdx_ = -1;
   this.failed_ = false;
   this.steps_ = steps;
   this.callback_ = callback;
   this.failureCallback_ = failureCallback;
   this.logger = logger;
   this.name = name;
@@ skipping 92 matching lines @@
   this.nextStep.apply(this, arguments);
 };
 
 /**
  * Add Function object mimics to FunctionSequence
  */
 FunctionSequence.prototype.apply_ = function(obj, args) {
   this.start.apply(this, args);
 };