Only log BWE updates if the actual estimate changed or if we have non-zero loss reports.

webrtc/modules/bitrate_controller/send_side_bandwidth_estimation.h

 /*
  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  *
  *  FEC and NACK added bitrate is handled outside class
@@ skipping 66 matching lines @@
   int expected_packets_since_last_loss_update_;
 
   uint32_t bitrate_;
   uint32_t min_bitrate_configured_;
   uint32_t max_bitrate_configured_;
   int64_t last_low_bitrate_log_ms_;
 
   bool has_decreased_since_last_fraction_loss_;
   int64_t time_last_receiver_block_ms_;
   uint8_t last_fraction_loss_;
+  uint8_t last_logged_fraction_loss_;
   int64_t last_round_trip_time_ms_;
 
   uint32_t bwe_incoming_;
   uint32_t delay_based_bitrate_bps_;
   int64_t time_last_decrease_ms_;
   int64_t first_report_time_ms_;
   int initially_lost_packets_;
   int bitrate_at_2_seconds_kbps_;
   UmaState uma_update_state_;
   std::vector<bool> rampup_uma_stats_updated_;
   RtcEventLog* event_log_;
+  int64_t last_rtc_event_log_ms_;
 };
 }  // namespace webrtc
 #endif  // WEBRTC_MODULES_BITRATE_CONTROLLER_SEND_SIDE_BANDWIDTH_ESTIMATION_H_