MessagePort API is likely to change to be usable for communication with workers. So, it would be counter-productive to ship it in its current state, but I'd like to keep the implementation around for experiments for now. Patch to disable MesagePort/MessageChannel by default forthcoming.
Created attachment 25210 [details] proposed patch
Comment on attachment 25210 [details] proposed patch rs=me
Committed revision 38547.
...and revision 38550 for WebKitTools.