Revert "Reland of Remove SendPacer from ViEEncoder

webrtc/modules/bitrate_controller/bitrate_controller_impl.cc

Index: webrtc/modules/bitrate_controller/bitrate_controller_impl.cc
diff --git a/webrtc/modules/bitrate_controller/bitrate_controller_impl.cc b/webrtc/modules/bitrate_controller/bitrate_controller_impl.cc
index 09652d84194207b9742f10e0bb67690a1dd1a27b..3c0d37c3b04c66c974f9b8830ba7a4cb47c127db 100644
--- a/webrtc/modules/bitrate_controller/bitrate_controller_impl.cc
+++ b/webrtc/modules/bitrate_controller/bitrate_controller_impl.cc
@@ -83,10 +83,6 @@ BitrateController* BitrateController::CreateBitrateController(
   return new BitrateControllerImpl(clock, observer);
 }
 
-BitrateController* BitrateController::CreateBitrateController(Clock* clock) {
-  return new BitrateControllerImpl(clock, nullptr);
-}
-
 BitrateControllerImpl::BitrateControllerImpl(Clock* clock,
                                              BitrateObserver* observer)
     : clock_(clock),
@@ -98,8 +94,8 @@ BitrateControllerImpl::BitrateControllerImpl(Clock* clock,
       last_fraction_loss_(0),
       last_rtt_ms_(0),
       last_reserved_bitrate_bps_(0) {
-  // This calls the observer_ if set, which means that the observer provided by
-  // the user must be ready to accept a bitrate update when it constructs the
+  // This calls the observer_, which means that the observer provided by the
+  // user must be ready to accept a bitrate update when it constructs the
   // controller. We do this to avoid having to keep synchronized initial values
   // in both the controller and the allocator.
   MaybeTriggerOnNetworkChanged();
@@ -203,15 +199,11 @@ void BitrateControllerImpl::OnReceivedRtcpReceiverReport(
 }
 
 void BitrateControllerImpl::MaybeTriggerOnNetworkChanged() {
-  if (!observer_)
-    return;
-
-  uint32_t bitrate_bps;
+  uint32_t bitrate;
   uint8_t fraction_loss;
   int64_t rtt;
-
-  if (GetNetworkParameters(&bitrate_bps, &fraction_loss, &rtt))
-    observer_->OnNetworkChanged(bitrate_bps, fraction_loss, rtt);
+  if (GetNetworkParameters(&bitrate, &fraction_loss, &rtt))
+    observer_->OnNetworkChanged(bitrate, fraction_loss, rtt);
 }
 
 bool BitrateControllerImpl::GetNetworkParameters(uint32_t* bitrate,