Add logic for a client to enable pacing via config to the QUIC sent

net/quic/quic_sent_packet_manager.cc

Index: net/quic/quic_sent_packet_manager.cc
diff --git a/net/quic/quic_sent_packet_manager.cc b/net/quic/quic_sent_packet_manager.cc
index 41221ccee2dd25daf69556aff1df6b6a5b37b281..8fb27170ef3f0af8af05520eb7eb8718cee88b7a 100644
--- a/net/quic/quic_sent_packet_manager.cc
+++ b/net/quic/quic_sent_packet_manager.cc
@@ -114,8 +114,13 @@ void QuicSentPacketManager::SetFromConfig(const QuicConfig& config) {
     send_algorithm_.reset(
         SendAlgorithmInterface::Create(clock_, &rtt_stats_, kReno, stats_));
   }
-  if (config.HasReceivedConnectionOptions() &&
-      ContainsQuicTag(config.ReceivedConnectionOptions(), kPACE)) {
+  if (is_server_) {
+    if (config.HasReceivedConnectionOptions() &&
+        ContainsQuicTag(config.ReceivedConnectionOptions(), kPACE)) {
+      EnablePacing();
+    }
+  } else if (config.HasSendConnectionOptions() &&
+             ContainsQuicTag(config.SendConnectionOptions(), kPACE)) {
     EnablePacing();
   }
   // TODO(ianswett): Remove the "HasReceivedLossDetection" branch once