Relanding "Pass time constant to bwe smoothing filter."

webrtc/video/video_send_stream.cc

Index: webrtc/video/video_send_stream.cc
diff --git a/webrtc/video/video_send_stream.cc b/webrtc/video/video_send_stream.cc
index 4416fb99bbedfa6647bff36425c482a21fc9ade5..a1c1a0b0795f18d221f5ac13a0e24e0a6289dfae 100644
--- a/webrtc/video/video_send_stream.cc
+++ b/webrtc/video/video_send_stream.cc
@@ -333,7 +333,8 @@ class VideoSendStreamImpl : public webrtc::BitrateAllocatorObserver,
   // Implements BitrateAllocatorObserver.
   uint32_t OnBitrateUpdated(uint32_t bitrate_bps,
                             uint8_t fraction_loss,
-                            int64_t rtt) override;
+                            int64_t rtt,
+                            int64_t probing_interval_ms) override;
 
   // Implements webrtc::VCMProtectionCallback.
   int ProtectionRequest(const FecProtectionParams* delta_params,
@@ -1170,7 +1171,8 @@ void VideoSendStreamImpl::SignalNetworkState(NetworkState state) {
 
 uint32_t VideoSendStreamImpl::OnBitrateUpdated(uint32_t bitrate_bps,
                                                uint8_t fraction_loss,
-                                               int64_t rtt) {
+                                               int64_t rtt,
+                                               int64_t probing_interval_ms) {
   RTC_DCHECK_RUN_ON(worker_queue_);
   RTC_DCHECK(payload_router_.active())
       << "VideoSendStream::Start has not been called.";