Context: http://krijnhoetmer.nl/irc-logs/whatwg/20130426#l-1104
Per the specification there is no reason for failure here. Everything that is needed from XMLHttpRequest's associated Document has been estalished so there is no reason for the fetch to fail. It seems like the specification does not match what is implemented. We should probably figure out what actually happens and whether that's a better model. -- http://annevankesteren.nl/
