There are some corner cases where we try to attach StreamFilter endpoints to a
channel after its IPC has been closed from from the other side, but request
listeners haven't been notified. This causes crashes in any of several places.
This patch changes nsHttpChannel::ProcessId to return 0 when IPC is closed, so
callers can detect that it's no longer possible to attach endpoints to it.
MozReview-Commit-ID: BZTOqezih0P
--HG--
extra : rebase_source : dfdb5bf7a11fccea51a1fbb161e688f10167da30