A previous change caused a regression in the congestion window behavior.
This CL restores previous behavior.
Bug: webrtc:8415
Change-Id: Id2e42d66bcfb58780c98da2227da39b970f26f0e
Reviewed-on: https://webrtc-review.googlesource.com/79483
Reviewed-by: Ying Wang <yinwa@webrtc.org>
Commit-Queue: Sebastian Jansson <srte@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23428}