This is the first step to removing streams from third_party/webrtc. RtpReceiverInterface::streams() will have to be removed separately. See https://crbug.com/webrtc/9480 for more information. Bug: webrtc:9480 Change-Id: I6f9e6ddcda5e2245cc601d2cc6205b7b363f73ef Reviewed-on: https://webrtc-review.googlesource.com/86840 Reviewed-by: Seth Hampson <shampson@webrtc.org> Reviewed-by: Steve Anton <steveanton@webrtc.org> Commit-Queue: Henrik Boström <hbos@webrtc.org> Cr-Commit-Position: refs/heads/master@{#23929}