基于丢包 RR报文
RTCPReceiver::IncomingPacket
	|
RTCPReceiver::TriggerCallbacksFromRtcpPacket
	|
BitrateControllerImpl::OnReceivedRtcpReceiverReport
	|
SendSideBandwidthEstimation::UpdateReceiverBlock
	|
SendSideBandwidthEstimation::UpdatePacketsLost
	|
SendSideBandwidthEstimation::UpdateEstimate
	|
SendSideBandwidthEstimation::CapBitrateToThresholds
	|
current_bitrate_bps_ = bitrate_bps;


基于延时 TransportFeedback报文
RTCPReceiver::IncomingPacket
	|
RTCPReceiver::TriggerCallbacksFromRtcpPacket
	|
SendSideCongestionController::OnTransportFeedback
	|
BitrateControllerImpl::OnDelayBasedBweResult
	|
SendSideBandwidthEstimation::UpdateDelayBasedEstimate
	|
SendSideBandwidthEstimation::CapBitrateToThresholds
	|
current_bitrate_bps_ = bitrate_bps;