Log the quic version for internal server tracing. Not used in production.

net/quic/quic_connection.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/quic/quic_connection.h"
 
 #include <string.h>
 #include <sys/types.h>
 #include <algorithm>
 #include <iterator>
@@ skipping 347 matching lines @@
       // Might be old packets that were sent by the client before the version
       // was negotiated. Drop these.
       return false;
 
     default:
       DCHECK(false);
   }
 
   version_negotiation_state_ = NEGOTIATED_VERSION;
   visitor_->OnSuccessfulVersionNegotiation(received_version);
+  if (debug_visitor_.get() != NULL) {
+    debug_visitor_->OnSuccessfulVersionNegotiation(received_version);
+  }
   DVLOG(1) << ENDPOINT << "version negotiated " << received_version;
 
   // Store the new version.
   framer_.set_version(received_version);
 
   // TODO(satyamshekhar): Store the sequence number of this packet and close the
   // connection if we ever received a packet with incorrect version and whose
   // sequence number is greater.
   return true;
 }
@@ skipping 106 matching lines @@
                       << " without version flag before version negotiated.";
         // Packets should have the version flag till version negotiation is
         // done.
         CloseConnection(QUIC_INVALID_VERSION, false);
         return false;
       } else {
         DCHECK_EQ(1u, header.public_header.versions.size());
         DCHECK_EQ(header.public_header.versions[0], version());
         version_negotiation_state_ = NEGOTIATED_VERSION;
         visitor_->OnSuccessfulVersionNegotiation(version());
+        if (debug_visitor_.get() != NULL) {
+          debug_visitor_->OnSuccessfulVersionNegotiation(version());
+        }
       }
     } else {
       DCHECK(!header.public_header.version_flag);
       // If the client gets a packet without the version flag from the server
       // it should stop sending version since the version negotiation is done.
       packet_generator_.StopSendingVersion();
       version_negotiation_state_ = NEGOTIATED_VERSION;
       visitor_->OnSuccessfulVersionNegotiation(version());
+      if (debug_visitor_.get() != NULL) {
+        debug_visitor_->OnSuccessfulVersionNegotiation(version());
+      }
     }
   }
 
   DCHECK_EQ(NEGOTIATED_VERSION, version_negotiation_state_);
 
   --stats_.packets_dropped;
   DVLOG(1) << ENDPOINT << "Received packet header: " << header;
   last_header_ = header;
   DCHECK(connected_);
   return true;
@@ skipping 1479 matching lines @@
   // If we changed the generator's batch state, restore original batch state.
   if (!already_in_batch_mode_) {
     DVLOG(1) << "Leaving Batch Mode.";
     connection_->packet_generator_.FinishBatchOperations();
   }
   DCHECK_EQ(already_in_batch_mode_,
             connection_->packet_generator_.InBatchMode());
 }
 
 }  // namespace net