[MD settings] cast elements to cr_dialog

chrome/browser/resources/settings/certificate_manager_page/ca_trust_edit_dialog.js

 // Copyright 2016 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-ca-trust-edit-dialog' allows the user to
  *  - specify the trust level of a certificate authority that is being
  *    imported.
  *  - edit the trust level of an already existing certificate authority.
  */
@@ skipping 28 matching lines @@
     // A non existing |model.id| indicates that a new certificate is being
     // imported, otherwise an existing certificate is being edited.
     if (this.model.id) {
       this.browserProxy_.getCaCertificateTrust(this.model.id).then(
           /** @param {!CaTrustInfo} trustInfo */
           function(trustInfo) {
             this.trustInfo_ = trustInfo;
             this.$.dialog.open();
           }.bind(this));
     } else {
-      this.$.dialog.open();
+      /** @type {!CrDialogElement} */ (this.$.dialog).open();
     }
   },
 
   /** @private */
   onCancelTap_: function() {
-    this.$.dialog.close();
+    /** @type {!CrDialogElement} */ (this.$.dialog).close();
   },
 
   /** @private */
   onOkTap_: function() {
     this.$.spinner.active = true;
 
     var whenDone = this.model.id ?
         this.browserProxy_.editCaCertificateTrust(
             this.model.id, this.$.ssl.checked,
             this.$.email.checked, this.$.objSign.checked) :
         this.browserProxy_.importCaCertificateTrustSelected(
             this.$.ssl.checked, this.$.email.checked, this.$.objSign.checked);
 
     whenDone.then(function() {
       this.$.spinner.active = false;
-      this.$.dialog.close();
+      /** @type {!CrDialogElement} */ (this.$.dialog).close();
     }.bind(this),
     /** @param {!CertificatesError} error */
     function(error) {
-      this.$.dialog.close();
+      /** @type {!CrDialogElement} */ (this.$.dialog).close();
       this.fire('certificates-error', error);
     }.bind(this));
   },
 });