- Previously, if a port is disconnected by the other end, then memory
would be leaked to `ProxyMessenger.ports` in ExtensionParent.jsm.
To fix this, the port descriptor is now saved separately, keyed by
port ID instead of message manager.
- Previously, when a message manager was disconnected (e.g. window
closed/tab crashed), the port is disconnected only if the port was
created from that page.
This patch adds bookkeeping to keep track of the message managers at
both the sender and receiver's side, so that the port is always
disconnected when the other side goes away.
- The new test browser_ext_port_disconnect_on_crash.js checks whether
the ports are disconnected as expected. Previously, the subtest
connect_from_tab_to_bg_and_crash_tab failed because of the previous
point.
- Although not as deterministic as the crash test, the new
browser_ext_port_disconnect_on_window_close.js reproduces the original
test failure and serves as a regression test for the bug.
- Previously, the data structure in ProxyMessenger.ports contained
the original `sender` and `recipient`. For the purpose of sending
port disconnection messages, these are not necessary and therefore
they have been removed.
- Fix incorrect JSDoc (type of portId is number, not string)
MozReview-Commit-ID: BoaKRVAUKuq
77a949f94f
