[whatwg] Declarative unload data

[Boris Zbarsky]

On 8/22/12 4:53 PM, Mark Watson wrote:
> Also, we've considered "heartbeat" type solutions, which whilst better than nothing are vulnerable to an attack in which the heartbeat messages are blocked.

I'd like to understand this better.  Would such an attack not also work 
on XHR?

(I realize there are other issues with a heartbeat ping; just wanted to 
make sure I understand this particular issue properly.)

-Boris