Deprecate FLAGS_quic_drop_non_awaited_packets.

net/quic/quic_connection.cc

Index: net/quic/quic_connection.cc
diff --git a/net/quic/quic_connection.cc b/net/quic/quic_connection.cc
index fadf5f4514fadfe25e7d04b616db418fabca166e..1598d6164770402dfb30c60678f1eff05a847ad3 100644
--- a/net/quic/quic_connection.cc
+++ b/net/quic/quic_connection.cc
@@ -644,8 +644,7 @@ bool QuicConnection::OnUnauthenticatedHeader(const QuicPacketHeader& header) {
 
   // If this packet has already been seen, or the sender has told us that it
   // will not be retransmitted, then stop processing the packet.
-  if (FLAGS_quic_drop_non_awaited_packets &&
-      !received_packet_manager_.IsAwaitingPacket(header.packet_number)) {
+  if (!received_packet_manager_.IsAwaitingPacket(header.packet_number)) {
     DVLOG(1) << ENDPOINT << "Packet " << header.packet_number
              << " no longer being waited for.  Discarding.";
     if (debug_visitor_ != nullptr) {
@@ -1412,18 +1411,6 @@ bool QuicConnection::ProcessValidatedPacket(const QuicPacketHeader& header) {
     return false;
   }
 
-  // If this packet has already been seen, or the sender has told us that it
-  // will not be retransmitted, then stop processing the packet.
-  if (!FLAGS_quic_drop_non_awaited_packets &&
-      !received_packet_manager_.IsAwaitingPacket(header.packet_number)) {
-    DVLOG(1) << ENDPOINT << "Packet " << header.packet_number
-             << " no longer being waited for.  Discarding.";
-    if (debug_visitor_ != nullptr) {
-      debug_visitor_->OnDuplicatePacket(header.packet_number);
-    }
-    return false;
-  }
-
   if (version_negotiation_state_ != NEGOTIATED_VERSION) {
     if (perspective_ == Perspective::IS_SERVER) {
       if (!header.public_header.version_flag) {
@@ -2025,8 +2012,7 @@ void QuicConnection::MaybeProcessRevivedPacket() {
 QuicFecGroup* QuicConnection::GetFecGroup() {
   QuicFecGroupNumber fec_group_num = last_header_.fec_group;
   if (fec_group_num == 0 ||
-      (FLAGS_quic_drop_non_awaited_packets &&
-       fec_group_num <
+      (fec_group_num <
            received_packet_manager_.peer_least_packet_awaiting_ack() &&
        !ContainsKey(group_map_, fec_group_num))) {
     // If the group number is below peer_least_packet_awaiting_ack and this
@@ -2129,9 +2115,7 @@ void QuicConnection::CloseFecGroupsBefore(QuicPacketNumber packet_number) {
   FecGroupMap::iterator it = group_map_.begin();
   while (it != group_map_.end()) {
     // If the group doesn't protect this packet we can ignore it.
-    if ((!FLAGS_quic_drop_non_awaited_packets &&
-         last_header_.fec_group == it->first) ||
-        !it->second->IsWaitingForPacketBefore(packet_number)) {
+    if (!it->second->IsWaitingForPacketBefore(packet_number)) {
       ++it;
       continue;
     }