Add GLS to the feedback whitelist

BUG=426600

Review URL: https://codereview.chromium.org/645703004

Cr-Commit-Position: refs/heads/master@{#301049}

chrome/browser/resources/feedback/js/event_handler.js

@@ -46,6 +46,8 @@ var whitelistedExtensionIds = [
   'ljclpkphhpbpinifbeabbhlfddcpfdde', // Hangouts Extension
   'nckgahadagoaajjgafhacjanaoiihapd', // Hangouts Extension
   'knipolnnllmklapflnccelgolnpehhpl', // Hangouts Extension
+  'dogkdgiahcdchbabhdmpbhlfoddjined', // GLS nightly
+  'khkjfddibboofomnlkndfedpoccieiee', // GLS stable
 ];
 
 /**