Hook up libjingle WebRtcVoiceEngine to Call API for combined A/V BWE.

BUG=4574,3109
R=pbos@webrtc.org, tommi@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/49269004

Cr-Commit-Position: refs/heads/master@{#9150}
15 files changed