Run a gist, just like bl.ocks.org
Due to Chrome's content security policy:
- Only gist-relative urls and https://github.com, https://rawgithub.com, and https://ajax.googleapis.com are allowed
- Read http://developer.chrome.com/extensions/getstarted.html
- Visit a gist page like https://gist.github.com/keeyip/6320579, and a run button will appear in the address bar