Use a separate window to notify the user that permissions are required.

remoting/webapp/app_remoting/js/ar_auth_dialog.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.
+
+/** @suppress {duplicate} */
+var remoting = remoting || {};
+
+(function() {
+
+'use strict';
+
+var instance_ = null;
+
+/**
+ * @constructor
+ * @implements {remoting.Identity.ConsentDialog}
+ * @private
+ */
+remoting.AuthDialog = function() {
+  /** @private {base.Deferred} */
+  this.deferred_ = null;
+};
+
+/**
+ * @return {Promise} A Promise object that resolves when the user clicks on the
+ *   auth button.
+ */
+remoting.AuthDialog.prototype.show = function() {
+  if (!this.deferred_) {
+    this.deferred_ = new base.Deferred();
+    remoting.MessageWindow.showMessageWindow(
+        l10n.getTranslationOrError(/*i18n-content*/'MODE_AUTHORIZE'),
+        l10n.getTranslationOrError(/*i18n-content*/'DESCRIPTION_AUTHORIZE'),
+        l10n.getTranslationOrError(/*i18n-content*/'CONTINUE_BUTTON'),
+        this.onOk_.bind(this));
+  }
+  return this.deferred_.promise();
+};
+
+/**
+ * @return {remoting.AuthDialog}
+ */
+remoting.AuthDialog.getInstance = function() {

[Jamie, 2015/03/21 01:18:23]

I would prefer that this getInstance() singleton is removed in favour of a
getAuthDialog() method on the delegate, but since I'm not sure what the future
of the delegate is, I've left it for now.

[garykac, 2015/03/23 23:25:33]

Add a TODO?

[Jamie, 2015/04/15 00:02:57]

There's one in auth_init.js which I think applies.

+  if (!instance_) {
+    instance_ = new remoting.AuthDialog();
+  }
+  return instance_;
+};
+
+remoting.AuthDialog.prototype.onOk_ = function() {
+  base.debug.assert(this.deferred_ !== null);
+  this.deferred_.resolve();
+  this.deferred_ = null;
+};
+
+})();