REGRESSION (149389) Main resources converted to downloads are immediately cancelled
The NetworkResourceLoader needs to know its handle should not be cancelled.
In radar as <rdar://problem/13795795>
I tried a patch that clears m_handle and keeps track of the ref()/deref() self state via a new bool, but because of the threading involved that ran into bizarre problems we don't have time to explore right now.
Prepping a patch that is probably a little worse but definitely works.
Alexey reviewed this patch over my shoulder. Landing soon.