Code review comment for lp:~nick-dedekind/mir/trusted_sessions

bool shell::TrustSession::add_trusted_child(std::shared_ptr<shell::Session> const& session) = 0;

I'm not convinced that TrustSession *owns* Session is the correct model. It means that if a client disconnects while in a trust session the Mir Session remains alive. Which is confusing at best.

I note that in practice scene::TrustSession only keeps weak_ptr<Session> which is a better reflection of the relationship. However, I still think that the relationship between TrustSession and Session better modeled as an association than as attributes.