Temporary: Detect WebSocket destruction order problem

net/http/http_network_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/http/http_network_session.h"
 
 #include <utility>
 
 #include "base/atomic_sequence_num.h"
 #include "base/compiler_specific.h"
@@ skipping 238 matching lines @@
   http_server_properties_->SetMaxServerConfigsStoredInProperties(
       params.quic_max_server_configs_stored_in_properties);
 
   memory_pressure_listener_.reset(new base::MemoryPressureListener(base::Bind(
       &HttpNetworkSession::OnMemoryPressure, base::Unretained(this))));
 }
 
 HttpNetworkSession::~HttpNetworkSession() {
   base::STLDeleteElements(&response_drainers_);
   spdy_session_pool_.CloseAllSessions();
+
+  // TODO(ricea): Remove this by October 2017. See bug 641013.
+  CHECK_EQ(active_websockets_, 0);
 }
 
 void HttpNetworkSession::AddResponseDrainer(HttpResponseBodyDrainer* drainer) {
   DCHECK(!base::ContainsKey(response_drainers_, drainer));
   response_drainers_.insert(drainer);
 }
 
 void HttpNetworkSession::RemoveResponseDrainer(
     HttpResponseBodyDrainer* drainer) {
   DCHECK(base::ContainsKey(response_drainers_, drainer));
@@ skipping 153 matching lines @@
     case base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_NONE:
       break;
     case base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_MODERATE:
     case base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_CRITICAL:
       CloseIdleConnections();
       break;
   }
 }
 
 }  // namespace net