Remove the using_pacing argument from QuicSentPacketManager::SetFromConfig because it's always true.

net/quic/congestion_control/pacing_sender.cc

Index: net/quic/congestion_control/pacing_sender.cc
diff --git a/net/quic/congestion_control/pacing_sender.cc b/net/quic/congestion_control/pacing_sender.cc
index f656001e918ec8cdb3a7b6767d676476f3cea76d..54c97bf6f79c06b67791ed354de9124e4019f185 100644
--- a/net/quic/congestion_control/pacing_sender.cc
+++ b/net/quic/congestion_control/pacing_sender.cc
@@ -21,10 +21,8 @@ PacingSender::PacingSender(SendAlgorithmInterface* sender,
 PacingSender::~PacingSender() {}
 
 void PacingSender::SetFromConfig(const QuicConfig& config,
-                                 Perspective perspective,
-                                 bool using_pacing) {
-  DCHECK(using_pacing);
-  sender_->SetFromConfig(config, perspective, using_pacing);
+                                 Perspective perspective) {
+  sender_->SetFromConfig(config, perspective);
 }
 
 bool PacingSender::ResumeConnectionState(