This CL contains only the changes necessary to make the switch to the new jitter
buffer, clean up will be done in follow up CLs.
In this CL:
- Removed the WebRTC-NewVideoJitterBuffer experiment and made the
new video jitter buffer the default one.
- Moved WebRTC.Video.KeyFramesReceivedInPermille and
WebRTC.Video.JitterBufferDelayInMs to the ReceiveStatisticsProxy.
BUG=webrtc:5514
Review-Url: https://codereview.webrtc.org/2627463004
Cr-Commit-Position: refs/heads/master@{#16114}