[MD settings] cast elements to cr_dialog

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

Index: chrome/browser/resources/settings/certificate_manager_page/ca_trust_edit_dialog.js
diff --git a/chrome/browser/resources/settings/certificate_manager_page/ca_trust_edit_dialog.js b/chrome/browser/resources/settings/certificate_manager_page/ca_trust_edit_dialog.js
index a7071316ccca947a7383236491b38c03bd52b514..08de7fa22f40107586c5e7665192649b8cabac23 100644
--- a/chrome/browser/resources/settings/certificate_manager_page/ca_trust_edit_dialog.js
+++ b/chrome/browser/resources/settings/certificate_manager_page/ca_trust_edit_dialog.js
@@ -46,13 +46,13 @@ Polymer({
             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 */
@@ -68,11 +68,11 @@ Polymer({
 
     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));
   },