Remove FEC related connection options and update FEC related comment in code base.

net/quic/quic_connection_stats.h

Index: net/quic/quic_connection_stats.h
diff --git a/net/quic/quic_connection_stats.h b/net/quic/quic_connection_stats.h
index 2787612966a983a2ea7cf8456893e28af154734e..b955b661b02eff2eb41761de51d7c934086c9c19 100644
--- a/net/quic/quic_connection_stats.h
+++ b/net/quic/quic_connection_stats.h
@@ -26,7 +26,7 @@ struct NET_EXPORT_PRIVATE QuicConnectionStats {
       std::ostream& os,
       const QuicConnectionStats& s);
 
-  QuicByteCount bytes_sent;  // Includes retransmissions, fec.
+  QuicByteCount bytes_sent;  // Includes retransmissions.
   QuicPacketCount packets_sent;
   // Non-retransmitted bytes sent in a stream frame.
   QuicByteCount stream_bytes_sent;
@@ -35,7 +35,7 @@ struct NET_EXPORT_PRIVATE QuicConnectionStats {
 
   // These include version negotiation and public reset packets, which do not
   // have packet numbers or frame data.
-  QuicByteCount bytes_received;  // Includes duplicate data for a stream, fec.
+  QuicByteCount bytes_received;  // Includes duplicate data for a stream.
   // Includes packets which were not processable.
   QuicPacketCount packets_received;
   // Excludes packets which were not processable.
@@ -55,7 +55,6 @@ struct NET_EXPORT_PRIVATE QuicConnectionStats {
   // Number of packets lost exiting slow start.
   QuicPacketCount slowstart_packets_lost;
 
-  QuicPacketCount packets_revived;
   QuicPacketCount packets_dropped;  // Duplicate or less than least unacked.
   size_t crypto_retransmit_count;
   // Count of times the loss detection alarm fired.  At least one packet should