Cancel IPv6 probe jobs during shutdown....

net/base/host_resolver_impl.cc

 // Copyright (c) 2010 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/base/host_resolver_impl.h"
 #include "net/base/net_log.h"
 
 #include <cmath>
 #include <deque>
 
@@ skipping 833 matching lines @@
   Flush();  // Give initial setup call.
 }
 
 void HostResolverImpl::Shutdown() {
   shutdown_ = true;
 
   // Cancel the outstanding jobs.
   for (JobMap::iterator it = jobs_.begin(); it != jobs_.end(); ++it)
     it->second->Cancel();
   jobs_.clear();
+  DiscardIPv6ProbeJob();
 }
 
 void HostResolverImpl::ClearRequestsTrace() {
   if (requests_trace_)
     requests_trace_->Clear();
 }
 
 void HostResolverImpl::EnableRequestsTracing(bool enable) {
   requests_trace_ = enable ? new RequestsTrace : NULL;
   if (enable) {
@@ skipping 207 matching lines @@
     net_log.EndEvent(NetLog::TYPE_HOST_RESOLVER_IMPL_OBSERVER_ONCANCEL);
   }
 
   net_log.EndEvent(NetLog::TYPE_HOST_RESOLVER_IMPL);
 }
 
 void HostResolverImpl::Flush() {
   if (cache_.get())
     cache_->clear();
   if (ipv6_probe_monitoring_) {
+    DCHECK(!shutdown_);
+    if (shutdown_)
+      return;
     DiscardIPv6ProbeJob();
     ipv6_probe_job_ = new IPv6ProbeJob(this);
     ipv6_probe_job_->Start();
   }
 }
 
 void HostResolverImpl::DiscardIPv6ProbeJob() {
   if (ipv6_probe_job_.get()) {
     ipv6_probe_job_->Cancel();
     ipv6_probe_job_ = NULL;
@@ skipping 94 matching lines @@
     if (r == req)
       return error;
 
     r->OnComplete(error, AddressList());
   }
 
   return ERR_IO_PENDING;
 }
 
 }  // namespace net