mCanSend was being cleared in ActorDestroy which is fine, but we
actually cannot reliably send IPC messages from CompositorBridgeParent
after we get a RecvWillClose message, because that's the last thing that
the child side sends before it gets destroyed. After the WillClose
message there's no guarantee that the child side actor will still be
alive. So this patch also sets mCanSend to false in RecvWillClose.
mCanSend is only used in two places, both of which have to do with the
APZ metrics-sharing code, so this shouldn't have any unexpected
side-effects. It is needed for the next patch.
MozReview-Commit-ID: 8CuFienWVUU
--HG--
extra : rebase_source : 11e4455ffd8cd281d0a16ca34feb63fa89338ccc
9c89bea7ea