Simplify directory initialization in Files app.

chrome/browser/resources/file_manager/common/js/util.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.
 
 'use strict';
 
 /**
  * Namespace for utility functions.
  */
 var util = {};
@@ skipping 654 matching lines @@
  */
 util.createChild = function(parent, opt_className, opt_tag) {
   var child = parent.ownerDocument.createElement(opt_tag || 'div');
   if (opt_className)
     child.className = opt_className;
   parent.appendChild(child);
   return child;
 };
 
 /**
- * Update the app state.
+ * Updates the app state.
+ * TODO(mtomasz): Migrate to URLs.
  *
- * @param {string} path Path to be put in the address bar after the hash.
- *   If null the hash is left unchanged.
- * @param {string|Object=} opt_param Search parameter. Used directly if string,
- *   stringified if object. If omitted the search query is left unchanged.
+ * @param {string} currentDirectoryPath Currently opened path. If null the path
+ *     is left unchanged.
+ * @param {string} selectionPath Currently selected path. If null the path is
+*      left unchanged.
+ * @param {string|Object=} opt_param Additional parameters, to be stored. If
+ *     null, then left unchanged.
  */
-util.updateAppState = function(path, opt_param) {
+util.updateAppState = function(currentDirectoryPath, selectionPath, opt_param) {
   window.appState = window.appState || {};
-  if (typeof opt_param == 'string')
-    window.appState.params = {};
-  else if (typeof opt_param == 'object')
+  if (opt_param !== undefined && opt_param !== null)
     window.appState.params = opt_param;
-  if (path)
-    window.appState.defaultPath = path;
+  if (currentDirectoryPath !== null)
+    window.appState.currentDirectoryPath = currentDirectoryPath;
+  if (selectionPath !== null)
+    window.appState.selectionPath = selectionPath;
   util.saveAppState();
-  return;
 };
 
 /**
- * Return a translated string.
+ * Returns a translated string.
  *
  * Wrapper function to make dealing with translated strings more concise.
  * Equivalent to loadTimeData.getString(id).
  *
  * @param {string} id The id of the string to return.
  * @return {string} The translated string.
  */
 function str(id) {
   return loadTimeData.getString(id);
 }
 
 /**
- * Return a translated string with arguments replaced.
+ * Returns a translated string with arguments replaced.
  *
  * Wrapper function to make dealing with translated strings more concise.
  * Equivalent to loadTimeData.getStringF(id, ...).
  *
  * @param {string} id The id of the string to return.
  * @param {...string} var_args The values to replace into the string.
  * @return {string} The translated string with replaced values.
  */
 function strf(id, var_args) {
   return loadTimeData.getStringF.apply(loadTimeData, arguments);
@@ skipping 542 matching lines @@
  * @enum {string}
  * @const
  */
 util.VolumeType = Object.freeze({
   DRIVE: 'drive',
   DOWNLOADS: 'downloads',
   REMOVABLE: 'removable',
   ARCHIVE: 'archive',
   CLOUD_DEVICE: 'cloud_device'
 });