Looks good. You just need to add the extra details to the language files to finish it off. If you go to your chat page then go directly to your online page it shows a blank in the location field.
Just add the lines below to the online.php language file and it will then display the location as chat rather than blank.
Once you have done that, you can edit the language file so that it will show who is using that page on Who's Online.
CP > Display Options > Languages > Language Editor > Choose Specific Language File: online.php > Go
Then add:
Key - chat
String - Viewing the Chat page
