Only use paced packets for estimating bitrate probes.

webrtc/modules/remote_bitrate_estimator/remote_bitrate_estimator_single_stream.cc

Index: webrtc/modules/remote_bitrate_estimator/remote_bitrate_estimator_single_stream.cc
diff --git a/webrtc/modules/remote_bitrate_estimator/remote_bitrate_estimator_single_stream.cc b/webrtc/modules/remote_bitrate_estimator/remote_bitrate_estimator_single_stream.cc
index dc7742808ff00ed92475ca22fa91124246f89692..6bbb34328e1ca313381f60a0e66f86905aaa3aa2 100644
--- a/webrtc/modules/remote_bitrate_estimator/remote_bitrate_estimator_single_stream.cc
+++ b/webrtc/modules/remote_bitrate_estimator/remote_bitrate_estimator_single_stream.cc
@@ -38,7 +38,8 @@ class RemoteBitrateEstimatorImpl : public RemoteBitrateEstimator {
 
   void IncomingPacket(int64_t arrival_time_ms,
                       size_t payload_size,
-                      const RTPHeader& header) override;
+                      const RTPHeader& header,
+                      bool was_paced) override;
   int32_t Process() override;
   int64_t TimeUntilNextProcess() override;
   void OnRttUpdate(int64_t rtt) override;
@@ -107,10 +108,10 @@ RemoteBitrateEstimatorImpl::~RemoteBitrateEstimatorImpl() {
   }
 }
 
-void RemoteBitrateEstimatorImpl::IncomingPacket(
-    int64_t arrival_time_ms,
-    size_t payload_size,
-    const RTPHeader& header) {
+void RemoteBitrateEstimatorImpl::IncomingPacket(int64_t arrival_time_ms,
+                                                size_t payload_size,
+                                                const RTPHeader& header,
+                                                bool was_paced) {
   uint32_t ssrc = header.ssrc;
   uint32_t rtp_timestamp = header.timestamp +
       header.extension.transmissionTimeOffset;