Connection not established: debug extention not installed

SHORT version:

I have JetBrains IDE Support 2.0.9 installed in Chrome (the browser I'm debugging in).

What debug extension does this refer to?

Where do I find it?

LOTS OF DETAIL

I'm trying to set .js breakpoints in a .php file and getting an error when I try to debug the first .php file choice (which should let me debug the javascript rather than the php).

I then see the script in the Console tab, which I thought might let me then set breakpoints. Is that right?

But I get "Connection not established". (see screenshot)

It further says "no debug extension is installed".

I have the JB Chrome IDE Support pluggin installed.

I have the "listening for debug connections" enabled.

I can't tell if I'm using the internal phpStorm Server or XAMPP (on my local machine)

FYI, my configuratiohn (displayed after I click the Update Interpreter)

PHP version: 5.5.8

PHP CLI: C:\Program Files (x86)\PHP\v5.5.8\php.exe
PHP CGI: C:\Program Files (x86)\PHP\v5.5.8\php-cgi.exe

Loaded Configuration File: Not Found

Debugger extension: Not Found

Loaded extensions:
bcmath, calendar, Core, ctype, date, dom, ereg, filter, ftp, hash, iconv, json, libxml, mcrypt, mhash, mysqlnd, odbc, pcre, PDO, Phar, Reflection, session, SimpleXML, SPL, standard, tokenizer, wddx, xml, xmlreader, xmlwriter, zip, zlib

Configuration options: