Address comments from cr 43769004.
- Remove unnecessary hop to worker from OnChannelRequestSignaling_s.
- Remove now-not-needed component param.
- Update documentation.

R=juberti@webrtc.org
BUG=4444

Review URL: https://webrtc-codereview.appspot.com/42839004

Cr-Commit-Position: refs/heads/master@{#8852}
2 files changed