Let ViEEncoder tell VideoSendStream about reconfigurations.

This cl change so that all encoder configuration changes are reported to VideoSendStream through the ViEEncoder.
Also, the PayLoadRouter is changed to never stop sending on a an ssrc due to the encoder video frame size changes. Instead, the number of sending streams is only decided by the number of sending ssrc.

This cl is a preparation for moving encoder reconfiguration due to input video frame size changes from WebRtcVideoSendStream to ViEEncoder.

BUG=webrtc:5687, webrtc:6371
R=mflodman@webrtc.org

Review URL: https://codereview.webrtc.org/2338133003 .

Cr-Original-Commit-Position: refs/heads/master@{#14371}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 512ecb320668bb1a70dd5bf56e6a5732a58f8743
7 files changed