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

net/quic/congestion_control/send_algorithm_interface.h

Index: net/quic/congestion_control/send_algorithm_interface.h
diff --git a/net/quic/congestion_control/send_algorithm_interface.h b/net/quic/congestion_control/send_algorithm_interface.h
index 7a49454ed07202420016e62d70ea3f71e322fa1f..db65ad4c36b488604381eedefe97c51d29e4c00f 100644
--- a/net/quic/congestion_control/send_algorithm_interface.h
+++ b/net/quic/congestion_control/send_algorithm_interface.h
@@ -40,8 +40,7 @@ class NET_EXPORT_PRIVATE SendAlgorithmInterface {
   virtual ~SendAlgorithmInterface() {}
 
   virtual void SetFromConfig(const QuicConfig& config,
-                             Perspective perspective,
-                             bool using_pacing) = 0;
+                             Perspective perspective) = 0;
 
   // Sets the number of connections to emulate when doing congestion control,
   // particularly for congestion avoidance.  Can be set any time.