The underlying CFNetwork call behaves differently on iOS so just pass nil for now.
Created attachment 227987 [details] Patch
Created attachment 227989 [details] Patch
Patch won't apply cleanly because it depends on my changes in bug 130861.
Comment on attachment 227989 [details] Patch Clearing flags on attachment: 227989 Committed r166387: <http://trac.webkit.org/changeset/166387>
All reviewed patches have been landed. Closing bug.