Greetings,
I'm not the sharpest tool in the toolbox, but my understanding here is that Chrome is throttling the http-bind requests and thus there's a period of time greater than the allowed timeouts between requests. If you check the timestamps of those sequential requests, you should notice a gap.
A hackish workaround I have done is to dramatically lengthen any server-side http-bind/bosh timeouts. This seems to keep the strophe sessions stable even under the throttling as the server will more patiently wait for the client to send the next sequential request.
HTH
daryl