No longer limit QUIC's max CWND to 200 packets. Protected by quic_dont_limit_max_cwnd.

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 2bdd1965a4b2fb79f106f3a3f92825331ac1e60d..c0369975f0f2f4ce5f2be6020b09332b7fce343c 100644
--- a/net/quic/quic_sent_packet_manager.cc
+++ b/net/quic/quic_sent_packet_manager.cc
@@ -173,7 +173,11 @@ void QuicSentPacketManager::SetFromConfig(const QuicConfig& config) {
             static_cast<QuicByteCount>(config.ReceivedSocketReceiveBuffer()));
     QuicByteCount max_cwnd_bytes = static_cast<QuicByteCount>(
         receive_buffer_bytes_ * kConservativeReceiveBufferFraction);
-    max_cwnd_bytes = min(max_cwnd_bytes, kMaxCongestionWindow * kDefaultTCPMSS);
+    if (!FLAGS_quic_dont_limit_max_cwnd) {
+      // TODO(ianswett): Remove kMaxCongestionWindow once deprecated.
+      max_cwnd_bytes =
+          min(max_cwnd_bytes, kMaxCongestionWindow * kDefaultTCPMSS);
+    }
     send_algorithm_->SetMaxCongestionWindow(max_cwnd_bytes);
   }
   send_algorithm_->SetFromConfig(config, perspective_);