Reuse FileTasks when entries are not changed.

ui/file_manager/file_manager/foreground/js/file_tasks.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.
 
 /**
  * Represents a collection of available tasks to execute for a specific list
  * of entries.
  *
  * @param {!VolumeManagerWrapper} volumeManager
  * @param {!MetadataModel} metadataModel
@@ skipping 50 matching lines @@
    */
   this.tasks_ = tasks;
 
   /**
    * @private {Object}
    * @const
    */
   this.defaultTask_ = defaultTask;
 };
 
+FileTasks.prototype = {
+  /**
+   * @return {!Array<!Entry>}
+   */
+  get entries() {
+    return this.entries_;
+  }
+};
+
 /**
  * The app ID of the video player app.
  * @const
  * @type {string}
  */
 FileTasks.VIDEO_PLAYER_ID = 'jcgeabjmjgoblfofpppfkcoakmfobdko';
 
 /**
  * The task id of the zip unpacker app.
  * @const
@@ skipping 737 matching lines @@
   }
   // If we haven't picked a default task yet, then just pick the first one
   // which is not generic file handler.
   for (var i = 0; i < tasks.length; i++) {
     if (!tasks[i].isGenericFileHandler) {
       return tasks[i];
     }
   }
   return opt_taskToUseIfNoDefault || null;
 };