Make sure websockets in workers don't leak DNS requests

WebSockets are available in WebWorkers now (https://bugzilla.mozilla.org/show_bug.cgi?id=504553). We need to double-check against fresh DNS leaks.

added MikePerry201506 in Legacy / Trac TorBrowserTeam201506 in Legacy / Trac component::applications/tor browser in Legacy / Trac ff38-esr in Legacy / Trac owner::mikeperry in Legacy / Trac priority::high in Legacy / Trac resolution::fixed in Legacy / Trac status::closed in Legacy / Trac tbb-5.0a3-essential in Legacy / Trac tbb-linkability in Legacy / Trac type::task in Legacy / Trac labels

Tag the set of things we should aim to understand/fix for the fist FF38-based TBB (5.0a3, on June 30th).

Trac:
Keywords: N/A deleted, tbb-5.0a3-essential added

Trac:
Status: new to assigned
Owner: tbb-team to mikeperry

Trac:
Keywords: N/A deleted, MikePerry201506, TorBrowserTeam201506 added

This did not turn up in my networking review as a new source of DNS or networking calls, and I looked at the specific patches and it appears that most of the work was to refactor the existing websocket code in way that it can be used from either worker threads or the main thread. I think this is fine.

Trac:
Resolution: N/A to fixed
Status: assigned to closed

closed

moved from legacy/trac#16334 (moved)

added Task label and removed 1 deleted label

added Linkability label and removed 1 deleted label