Temporarily store the raw QUIC packet in QuicConnection.

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 b107ee44ba1eaf514f70a288eefa3dc5bb86bde5..c49535589465045af279a804a296b483409bab42 100644
--- a/net/quic/quic_connection.cc
+++ b/net/quic/quic_connection.cc
@@ -244,6 +244,7 @@ QuicConnection::QuicConnection(QuicConnectionId connection_id,
       migrating_peer_port_(0),
       last_packet_decrypted_(false),
       last_size_(0),
+      current_packet_data_(nullptr),
       last_decrypted_packet_level_(ENCRYPTION_NONE),
       should_last_packet_instigate_acks_(false),
       largest_seen_packet_with_ack_(0),
@@ -1213,6 +1214,7 @@ void QuicConnection::ProcessUdpPacket(const IPEndPoint& self_address,
     debug_visitor_->OnPacketReceived(self_address, peer_address, packet);
   }
   last_size_ = packet.length();
+  current_packet_data_ = packet.data();
 
   if (FLAGS_check_peer_address_change_after_decryption) {
     last_packet_destination_address_ = self_address;
@@ -1244,6 +1246,7 @@ void QuicConnection::ProcessUdpPacket(const IPEndPoint& self_address,
     }
     DVLOG(1) << ENDPOINT << "Unable to process packet.  Last packet processed: "
              << last_header_.packet_number;
+    current_packet_data_ = nullptr;
     return;
   }
 
@@ -1251,6 +1254,7 @@ void QuicConnection::ProcessUdpPacket(const IPEndPoint& self_address,
   MaybeProcessUndecryptablePackets();
   MaybeSendInResponseToPacket();
   SetPingAlarm();
+  current_packet_data_ = nullptr;
 }
 
 void QuicConnection::CheckForAddressMigration(const IPEndPoint& self_address,
@@ -2340,4 +2344,11 @@ bool QuicConnection::ack_frame_updated() const {
   return received_packet_manager_.ack_frame_updated();
 }
 
+StringPiece QuicConnection::GetCurrentPacket() {
+  if (current_packet_data_ == nullptr) {
+    return StringPiece();
+  }
+  return StringPiece(current_packet_data_, last_size_);
+}
+
 }  // namespace net