Only create |remote_rate| when needed in RemoteBitrateEstimatorSingleStream.

webrtc/modules/remote_bitrate_estimator/remote_bitrate_estimator_single_stream.h

Index: webrtc/modules/remote_bitrate_estimator/remote_bitrate_estimator_single_stream.h
diff --git a/webrtc/modules/remote_bitrate_estimator/remote_bitrate_estimator_single_stream.h b/webrtc/modules/remote_bitrate_estimator/remote_bitrate_estimator_single_stream.h
index aa238d1e96ca555121f07884fe7c057998b4511a..31d796225a2b5cbb79c27044e009e2ddd8c82ee2 100644
--- a/webrtc/modules/remote_bitrate_estimator/remote_bitrate_estimator_single_stream.h
+++ b/webrtc/modules/remote_bitrate_estimator/remote_bitrate_estimator_single_stream.h
@@ -52,6 +52,10 @@ class RemoteBitrateEstimatorSingleStream : public RemoteBitrateEstimator {
   void GetSsrcs(std::vector<uint32_t>* ssrcs) const
       SHARED_LOCKS_REQUIRED(crit_sect_.get());
 
+  // Returns |remote_rate_| if the pointed to object exists,
+  // otherwise creates it.
+  AimdRateControl* GetRemoteRate() EXCLUSIVE_LOCKS_REQUIRED(crit_sect_.get());
+
   Clock* clock_;
   SsrcOveruseEstimatorMap overuse_detectors_ GUARDED_BY(crit_sect_.get());
   RateStatistics incoming_bitrate_ GUARDED_BY(crit_sect_.get());