I have some JavaScript code that sets up an event listener on
"TabOpen", and when I receive that event, I retrieve the browser by
doing this:

function tabOpenListener(event)
{
var b = event.target.linkedBrowser;

so now I want to have that same functionality in C++ (in a Firefox add-
on). I have a class that implements nsIDOMEventListener, and in my
HandleEvent() function I am getting an nsIDOMEvent *pEvent, I can then
call pEvent->GetTarget() to get a nsCOMPtr target,
so I can successfully do the equivalent of the "event.target" part of
the JavaScript code, but then what?

How do I do that magic "target.linkedBrowser" that is so easy in
JavaScript?

I've searched the Firefox site, and there doesn't appear to be any
interface that has a "linkedBrowser" element of any type (function or
data). I run into this a lot in C++, there seem to be values that
JavaScript is allowed to access that C++ isn't. Or is there some
hidden interface that all Firefox objects implement, something like
"nsIGetOtherStuff"?

Thanks,
Chris