MD Settings: Fix Reset profile dialog scenario that causes a crash.

chrome/browser/resources/settings/reset_page/reset_page.js

 // Copyright 2015 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
  * 'settings-reset-page' is the settings page containing reset
  * settings.
  *
  * Example:
  *
  *    <iron-animated-pages>
  *      <settings-reset-page prefs="{{prefs}}">
  *      </settings-reset-page>
  *      ... other pages ...
  *    </iron-animated-pages>
  */
 Polymer({
   is: 'settings-reset-page',
 
   properties: {
+<if expr="chromeos">
+    /** @private */
+    showPowerwashDialog_: Boolean,
+</if>
+
+    /** @private */
     allowPowerwash_: {
       type: Boolean,
       value: cr.isChromeOS ? loadTimeData.getBoolean('allowPowerwash') : false
     },
   },
 
   /** @private */
   onShowResetProfileDialog_: function() {
-    this.showDialog_('settings-reset-profile-dialog');
+    this.$.resetProfileDialog.get().open();
+  },
+
+<if expr="chromeos">
+  /** @private */
+  onShowPowerwashDialog_: function() {
+    this.showPowerwashDialog_ = true;
   },
 
   /** @private */
-  onShowPowerwashDialog_: function() {
-    this.showDialog_('settings-powerwash-dialog');
+  onPowerwashDialogClose_: function() {
+    this.showPowerwashDialog_ = false;
   },
-
-
-  /**
-   * Creates and shows the specified dialog.
-   * @param {string} dialogName
-   * @private
-   */
-  showDialog_: function(dialogName) {
-    var dialog = document.createElement(dialogName);
-    this.shadowRoot.appendChild(dialog);
-    dialog.open();
-
-    dialog.addEventListener('close', function() {
-      dialog.remove();
-    });
-  },
+</if>
 });