Refactor unittest trace printouts to a separate class.

This allows other tests/tools which don't depend on TestSuite to reuse the functionality.

BUG=

Review URL: https://webrtc-codereview.appspot.com/1245004

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@3721 4adac7df-926f-26a2-2b94-8c16560cd09d
5 files changed