Add benchmark option to run on workers

R=tyoshino@chromium.org

Review URL: https://codereview.appspot.com/135620043

git-svn-id: http://pywebsocket.googlecode.com/svn/trunk@842 4ff78f4a-9131-11de-b045-6380ec9940d4
Refactoring: rename responseType to dataType in xhr_benchmark

R=tyoshino@chromium.org

Review URL: https://codereview.appspot.com/137450043

git-svn-id: http://pywebsocket.googlecode.com/svn/trunk@843 4ff78f4a-9131-11de-b045-6380ec9940d4