* Revert clock.cc changes made in 6178, but keep the changes to the test.
* Use the new appoach proposed by jib in https://review.webrtc.org/10439004/ to fix the windows clock issue.

BUg=3325

R=niklas.enbom@webrtc.org, stefan@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/15569005

git-svn-id: http://webrtc.googlecode.com/svn/trunk@6273 4adac7df-926f-26a2-2b94-8c16560cd09d