Log created probe clusters to RtcEventLog.

webrtc/modules/remote_bitrate_estimator/test/packet_sender.cc

Index: webrtc/modules/remote_bitrate_estimator/test/packet_sender.cc
diff --git a/webrtc/modules/remote_bitrate_estimator/test/packet_sender.cc b/webrtc/modules/remote_bitrate_estimator/test/packet_sender.cc
index f0f57b4e70d98cd97ebdc9369df83d83cacbbe4b..e962c591a74d36a57053a2a44a587fe0996f4da3 100644
--- a/webrtc/modules/remote_bitrate_estimator/test/packet_sender.cc
+++ b/webrtc/modules/remote_bitrate_estimator/test/packet_sender.cc
@@ -156,8 +156,7 @@ uint32_t VideoSender::TargetBitrateKbps() {
 PacedVideoSender::PacedVideoSender(PacketProcessorListener* listener,
                                    VideoSource* source,
                                    BandwidthEstimatorType estimator)
-    : VideoSender(listener, source, estimator),
-      pacer_(&clock_, this) {
+    : VideoSender(listener, source, estimator), pacer_(&clock_, this, nullptr) {
   modules_.push_back(&pacer_);
   pacer_.SetEstimatedBitrate(source->bits_per_second());
 }