Don't close already closed connections in

net/quic/quic_client_session.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_client_session.h"
 
 #include "base/callback_helpers.h"
 #include "base/message_loop/message_loop.h"
 #include "base/metrics/histogram.h"
 #include "base/metrics/sparse_histogram.h"
@@ skipping 600 matching lines @@
                                                  QuicErrorCode quic_error) {
   if (!callback_.is_null()) {
     base::ResetAndReturn(&callback_).Run(net_error);
   }
   CloseAllStreams(net_error);
   CloseAllObservers(net_error);
   net_log_.AddEvent(
       NetLog::TYPE_QUIC_SESSION_CLOSE_ON_ERROR,
       NetLog::IntegerCallback("net_error", net_error));
 
-  connection()->CloseConnection(quic_error, false);
+  if (connection()->connected())
+    connection()->CloseConnection(quic_error, false);
   DCHECK(!connection()->connected());
 }
 
 void QuicClientSession::CloseAllStreams(int net_error) {
   while (!streams()->empty()) {
     ReliableQuicStream* stream = streams()->begin()->second;
     QuicStreamId id = stream->id();
     static_cast<QuicReliableClientStream*>(stream)->OnError(net_error);
     CloseStream(id);
   }
@@ skipping 96 matching lines @@
     RecordUnexpectedNotGoingAway(NOTIFY_FACTORY_OF_SESSION_CLOSED);
 
   going_away_ = true;
   DCHECK_EQ(0u, GetNumOpenStreams());
   // Will delete |this|.
   if (stream_factory_)
     stream_factory_->OnSessionClosed(this);
 }
 
 }  // namespace net