Revert "FieldTrial implementation for webrtc." (rev 6089) New wiring plans require it to be landed first in chrome for a cleaner roll of webrtc. BUG=crbug/367114 R=tommi@webrtc.org TBR=tommi@webrtc.org Review URL: https://webrtc-codereview.appspot.com/17479004 git-svn-id: http://webrtc.googlecode.com/svn/trunk@6122 4adac7df-926f-26a2-2b94-8c16560cd09d