work around missing XHR feature in chromium
work around missing XHR feature in chromium

http://code.google.com/p/chromium/issues/detail?id=119256

chris-morgan/rust-playpen,cogumbreiro/scribble-playpen,chris-morgan/rust-playpen,cogumbreiro/sepi-playpen,lastorset/rust-playpen,tilpner/rust-playpen,chris-morgan/rust-playpen,lastorset/rust-playpen,epdtry/cse333-rust-slides,cogumbreiro/scribble-playpen,plietar/pony-playpen,rust-lang/rust-playpen,Limvot/kraken-playpen,tilpner/rust-playpen,chris-morgan/rust-playpen,rust-lang/rust-playpen,cogumbreiro/sepi-playpen,Enamex/rust-playpen,drlagos/unify-playpen,rust-lang/rust-playpen,epdtry/cse333-rust-slides,tilpner/rust-playpen,Limvot/kraken-playpen,Enamex/rust-playpen,plietar/pony-playpen,tilpner/rust-playpen,lastorset/rust-playpen,plietar/pony-playpen,Enamex/rust-playpen,Enamex/rust-playpen,drlagos/mpisessions-playpen,rust-lang/rust-playpen,drlagos/mpisessions-playpen,plietar/pony-playpen,epdtry/cse333-rust-slides,lastorset/rust-playpen,Limvot/kraken-playpen,cogumbreiro/scribble-playpen,drlagos/unify-playpen,epdtry/cse333-rust-slides