Implement TraceCallback in a nested class of WebRtcVideoEngine.
This is to fix a race that occurs in unit tests when the tests inherit
from the engine class that also implements the callback interface for
tracing. If tracing happens while the most derived class is still being
constructed, we're in trouble.
So, instead, factoring out the TraceCallback implementation.
R=pbos@webrtc.org
BUG=
Review URL: https://webrtc-codereview.appspot.com/43489004
Cr-Commit-Position: refs/heads/master@{#8562}
git-svn-id: http://webrtc.googlecode.com/svn/trunk@8562 4adac7df-926f-26a2-2b94-8c16560cd09d
2 files changed
