Revert of Move RtcEventLog object from inside VoiceEngine to Call.

webrtc/modules/bitrate_controller/send_side_bandwidth_estimation.cc

Index: webrtc/modules/bitrate_controller/send_side_bandwidth_estimation.cc
diff --git a/webrtc/modules/bitrate_controller/send_side_bandwidth_estimation.cc b/webrtc/modules/bitrate_controller/send_side_bandwidth_estimation.cc
index e47d4917e9fd66e46cf765b12aff157e16e8b571..a1b78a257c6620fae93bbfd9dc1a7f53fceda5e4 100644
--- a/webrtc/modules/bitrate_controller/send_side_bandwidth_estimation.cc
+++ b/webrtc/modules/bitrate_controller/send_side_bandwidth_estimation.cc
@@ -44,7 +44,7 @@
 
 }  // namespace
 
-SendSideBandwidthEstimation::SendSideBandwidthEstimation(RtcEventLog* event_log)
+SendSideBandwidthEstimation::SendSideBandwidthEstimation()
     : lost_packets_since_last_loss_update_Q8_(0),
       expected_packets_since_last_loss_update_(0),
       bitrate_(0),
@@ -63,9 +63,7 @@
       bitrate_at_2_seconds_kbps_(0),
       uma_update_state_(kNoUpdate),
       rampup_uma_stats_updated_(kNumUmaRampupMetrics, false),
-      event_log_(event_log) {
-  RTC_DCHECK(event_log);
-}
+      event_log_(nullptr) {}
 
 SendSideBandwidthEstimation::~SendSideBandwidthEstimation() {}
 
@@ -229,9 +227,11 @@
       // rates).
       bitrate_ += 1000;
 
-      event_log_->LogBwePacketLossEvent(
-          bitrate_, last_fraction_loss_,
-          expected_packets_since_last_loss_update_);
+      if (event_log_) {
+        event_log_->LogBwePacketLossEvent(
+            bitrate_, last_fraction_loss_,
+            expected_packets_since_last_loss_update_);
+      }
     } else if (last_fraction_loss_ <= 26) {
       // Loss between 2% - 10%: Do nothing.
     } else {
@@ -250,9 +250,11 @@
             512.0);
         has_decreased_since_last_fraction_loss_ = true;
       }
-      event_log_->LogBwePacketLossEvent(
-          bitrate_, last_fraction_loss_,
-          expected_packets_since_last_loss_update_);
+      if (event_log_) {
+        event_log_->LogBwePacketLossEvent(
+            bitrate_, last_fraction_loss_,
+            expected_packets_since_last_loss_update_);
+      }
     }
   }
   bitrate_ = CapBitrateToThresholds(now_ms, bitrate_);
@@ -306,4 +308,9 @@
   }
   return bitrate;
 }
+
+void SendSideBandwidthEstimation::SetEventLog(RtcEventLog* event_log) {
+  event_log_ = event_log;
+}
+
 }  // namespace webrtc