Remove DCHECK in DialRegistry dtor. This may trigger on browser shutdown if

chrome/browser/extensions/api/dial/dial_registry.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 "chrome/browser/extensions/api/dial/dial_registry.h"
 
 #include "base/memory/scoped_ptr.h"
 #include "base/stl_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/time/time.h"
@@ skipping 24 matching lines @@
     refresh_interval_delta_(refresh_interval),
     expiration_delta_(expiration),
     max_devices_(max_devices),
     dial_api_(dial_api) {
   DCHECK(max_devices_ > 0);
   NetworkChangeNotifier::AddNetworkChangeObserver(this);
 }
 
 DialRegistry::~DialRegistry() {
   DCHECK(thread_checker_.CalledOnValidThread());
-  DCHECK_EQ(0, num_listeners_);
   NetworkChangeNotifier::RemoveNetworkChangeObserver(this);
 }
 
 DialService* DialRegistry::CreateDialService() {
   DCHECK(g_browser_process->net_log());
   return new DialServiceImpl(g_browser_process->net_log());
 }
 
 void DialRegistry::ClearDialService() {
   dial_.reset();
@@ skipping 266 matching lines @@
     case NetworkChangeNotifier::CONNECTION_BLUETOOTH:
       if (!dial_.get()) {
         VLOG(2) << "Connection detected, restarting discovery.";
         StartPeriodicDiscovery();
       }
       break;
   }
 }
 
 }  // namespace extensions