Both tests had been disabled since 2012. They could not simply be
reenabled: "last-pb-context-exited" is now fired from a private context
refcount kept on CanonicalBrowsingContext, which only counts content
browsing contexts, so the chrome windowless browser the tests used never
moved the count and the notification never fired. An attached content
context cannot have its origin attributes changed either, so the context
has to be created private.
test_pb_notification.js now uses XPCShellContentUtils to load a private
content page and closes it.
test_pb_notification_ipc.js is inverted. The private context can only be
created in the parent process, so the parent drives it and the child only
observes, which covers the ContentParent -> ContentChild relay of the
topic that the content process consumers depend on.
Differential Revision: https://phabricator.services.mozilla.com/D322105
Dan Mehic
0cb8ececef