Settings: Network: Handle getmanagerProperties error correctly

chrome/browser/resources/settings/internet_page/internet_known_networks_page.js

Index: chrome/browser/resources/settings/internet_page/internet_known_networks_page.js
diff --git a/chrome/browser/resources/settings/internet_page/internet_known_networks_page.js b/chrome/browser/resources/settings/internet_page/internet_known_networks_page.js
index 16e3b9e93b8f81464ad0bcd284068908e39e341a..839f41377e15059bfbb94411ddb383d1ddf2a389 100644
--- a/chrome/browser/resources/settings/internet_page/internet_known_networks_page.js
+++ b/chrome/browser/resources/settings/internet_page/internet_known_networks_page.js
@@ -154,6 +154,11 @@ Polymer({
     // preferable to initiating a query for every known network at load time.
     this.networkingPrivate.getManagedProperties(
         this.selectedGuid_, function(properties) {
+          if (chrome.runtime.lastError || !properties) {
+            this.showAddPreferred_ = false;
+            this.showRemovePreferred_ = false;
+            return;
+          }
           var preferred = button.hasAttribute('preferred');
           if (this.isNetworkPolicyEnforced(properties.Priority)) {
             this.showAddPreferred_ = false;