Move trace_event and associated files to webrtc/base.
Also starting to use TRACE_EVENT from thread.cc in webrtc/base, to track Invoke() calls.

BUG=
R=magjed@webrtc.org, tina.legrand@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/42769004

Cr-Commit-Position: refs/heads/master@{#8755}
git-svn-id: http://webrtc.googlecode.com/svn/trunk@8755 4adac7df-926f-26a2-2b94-8c16560cd09d
13 files changed