Log QUIC packet losses into net event log

R=rch@chromium.org

Change-Id: I3ff1bb22ead3a993ef0248814fa6b270ec2ace23
Reviewed-on: https://chromium-review.googlesource.com/1217917Reviewed-by: Ryan Hamilton <rch@chromium.org>
Commit-Queue: Ryan Hamilton <rch@chromium.org>
Cr-Commit-Position: refs/heads/master@{#590312}

net/log/net_log_event_type_list.h

@@ -1726,6 +1726,14 @@ EVENT_TYPE(QUIC_SESSION_PACKET_SENT)
 //   }
 EVENT_TYPE(QUIC_SESSION_PACKET_RETRANSMITTED)
 
+// Session declared a QUIC packet lost.
+//   {
+//     "transmission_type": <The quic::TransmissionType of the packet>,
+//     "packet_number": <The packet's full 64-bit number as a base-10 string>,
+//     "detection_time": <The time at which the packet was declared lost>
+//   }
+EVENT_TYPE(QUIC_SESSION_PACKET_LOST)
+
 // Session received a QUIC packet with a sequence number that had previously
 // been received.
 //   {

net/quic/quic_connection_logger.cc

@@ -73,6 +73,19 @@ std::unique_ptr<base::Value> NetLogQuicPacketRetransmittedCallback(
   return std::move(dict);
 }
 
+std::unique_ptr<base::Value> NetLogQuicPacketLostCallback(
+    quic::QuicPacketNumber packet_number,
+    quic::TransmissionType transmission_type,
+    quic::QuicTime detection_time,
+    NetLogCaptureMode /*capture_mode*/) {
+  auto dict = std::make_unique<base::DictionaryValue>();
+  dict->SetInteger("transmission_type", transmission_type);
+  dict->SetString("packet_number", base::NumberToString(packet_number));
+  dict->SetString("detection_time_us",
+                  base::Int64ToString(detection_time.ToDebuggingValue()));
+  return dict;
+}
+
 std::unique_ptr<base::Value> NetLogQuicDuplicatePacketCallback(
     quic::QuicPacketNumber packet_number,
     NetLogCaptureMode /* capture_mode */) {
@@ -469,6 +482,18 @@ void QuicConnectionLogger::OnPacketSent(
   }
 }
 
+void QuicConnectionLogger::OnPacketLoss(
+    quic::QuicPacketNumber lost_packet_number,
+    quic::TransmissionType transmission_type,
+    quic::QuicTime detection_time) {
+  if (!net_log_is_capturing_)
+    return;
+  net_log_.AddEvent(
+      NetLogEventType::QUIC_SESSION_PACKET_LOST,
+      base::Bind(&NetLogQuicPacketLostCallback, lost_packet_number,
+                 transmission_type, detection_time));
+}
+
 void QuicConnectionLogger::OnPingSent() {
   no_packet_received_after_ping_ = true;
 }

net/quic/quic_connection_logger.h

@@ -50,6 +50,9 @@ class NET_EXPORT_PRIVATE QuicConnectionLogger
                     quic::QuicPacketNumber original_packet_number,
                     quic::TransmissionType transmission_type,
                     quic::QuicTime sent_time) override;
+  void OnPacketLoss(quic::QuicPacketNumber lost_packet_number,
+                    quic::TransmissionType transmission_type,
+                    quic::QuicTime detection_time) override;
   void OnPingSent() override;
   void OnPacketReceived(const quic::QuicSocketAddress& self_address,
                         const quic::QuicSocketAddress& peer_address,