Gather histogram for received packets indicating losses.

net/quic/quic_connection_logger.h

Index: net/quic/quic_connection_logger.h
diff --git a/net/quic/quic_connection_logger.h b/net/quic/quic_connection_logger.h
index ed9577ac361761ec0b98805f6e5f7eead0de5da7..7272c386653632c1cbee4ecfa209e65d0a2a6632 100644
--- a/net/quic/quic_connection_logger.h
+++ b/net/quic/quic_connection_logger.h
@@ -5,7 +5,10 @@
 #ifndef NET_QUIC_QUIC_CONNECTION_LOGGER_H_
 #define NET_QUIC_QUIC_CONNECTION_LOGGER_H_
 
+#include <bitset>
+
 #include "net/base/ip_endpoint.h"
+#include "net/base/network_change_notifier.h"
 #include "net/quic/quic_connection.h"
 #include "net/quic/quic_protocol.h"
 
@@ -60,6 +63,13 @@ class NET_EXPORT_PRIVATE QuicConnectionLogger
   void OnSuccessfulVersionNegotiation(const QuicVersion& version);
 
  private:
+  // Do a factory get for an "Ack_" or "Nack_" style histogram for recording
+  // packet loss stats.
+  base::HistogramBase* GetAckHistogram(const char* ack_or_nack);
+  // At destruction time, this records results of |pacaket_received_| into
+  // histograms for specific connection types.
+  void RecordAckNackHistograms();
+
   BoundNetLog net_log_;
   // The last packet sequence number received.
   QuicPacketSequenceNumber last_received_packet_sequence_number_;
@@ -78,6 +88,13 @@ class NET_EXPORT_PRIVATE QuicConnectionLogger
   size_t num_truncated_acks_received_;
   // The kCADR value provided by the server in ServerHello.
   IPEndPoint client_address_;
+  // Vector of inital packets status' indexed by packet sequence numbers, where
+  // false means never received.  Zero is not a valid packet sequence number, so
+  // that offset is never used, and we'll track 100 packets.
+  std::bitset<101> packets_received_;
+  // The available type of connection (WiFi, 3G, etc.) when connection was first
+  // used.
+  NetworkChangeNotifier::ConnectionType connection_type_;
   DISALLOW_COPY_AND_ASSIGN(QuicConnectionLogger);
 };