QUIC - disable QUIC if packet loss rate is bad for a connection.

net/quic/quic_client_session.cc

Index: net/quic/quic_client_session.cc
diff --git a/net/quic/quic_client_session.cc b/net/quic/quic_client_session.cc
index 0625f08077d30c5c7c62a77e5668a72b8ee1c2d6..5c97667dc40ae84a697ddf3c04529f4e618430b9 100644
--- a/net/quic/quic_client_session.cc
+++ b/net/quic/quic_client_session.cc
@@ -593,6 +593,21 @@ void QuicClientSession::OnClosedStream() {
 }
 
 void QuicClientSession::OnCryptoHandshakeEvent(CryptoHandshakeEvent event) {
+  if (stream_factory_ && event == HANDSHAKE_CONFIRMED) {
+    float packet_loss_rate = logger_->PacketLossRate() / 10;

[Ryan Hamilton, 2015/03/23 02:31:06]

Why / 10?

[ramant (doing other things), 2015/03/24 03:07:22]

Remove the percent. Used fraction.

+    if (packet_loss_rate > stream_factory_->packet_loss_threshold()) {
+      stream_factory_->OnBadPacketLoss(server_id_);

[Ryan Hamilton, 2015/03/23 02:31:06]

I wonder if it might make more sense for this to be in the factory instead of
the session since it looks like the factory knows the loss threshold.

[ramant (doing other things), 2015/03/24 03:07:22]

Done.

+      // We abandon the connection if packet loss rate is too bad.
+      DVLOG(1) << "Closing session on bad packet loss rate: "
+               << packet_loss_rate;
+      UMA_HISTOGRAM_BOOLEAN("Net.QuicSession.HasBadPacketLossRate", true);
+      NotifyFactoryOfSessionGoingAway();
+      CloseSessionOnErrorInner(ERR_ABORTED, QUIC_BAD_PACKET_LOSS_RATE);
+      NotifyFactoryOfSessionClosedLater();

[Ryan Hamilton, 2015/03/23 02:31:06]

Is there a method the factory could call which would do all of this? Maybe
CloseSessionOnError?

[ramant (doing other things), 2015/03/24 03:07:22]

Called CloseSessionOnError from QuicStreamFactory.

Done.

+      return;
+    }
+  }
+
   if (!callback_.is_null() &&
       (!require_confirmation_ ||
        event == HANDSHAKE_CONFIRMED || event == ENCRYPTION_REESTABLISHED)) {