Allow HostCache to handle network changes itself

net/dns/host_resolver_impl.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/dns/host_resolver_impl.h"
 
 #if defined(OS_WIN)
 #include <Winsock2.h>
 #elif defined(OS_POSIX)
 #include <netdb.h>
@@ skipping 2434 matching lines @@
     job->ServeFromHosts();
   }
 }
 
 void HostResolverImpl::OnIPAddressChanged() {
   resolved_known_ipv6_hostname_ = false;
   last_ipv6_probe_time_ = base::TimeTicks();
   // Abandon all ProbeJobs.
   probe_weak_ptr_factory_.InvalidateWeakPtrs();
   if (cache_.get()) {
-    cache_->clear();
+    cache_->OnNetworkChange();
     cache_hit_callbacks_.clear();
   }
 #if defined(OS_POSIX) && !defined(OS_MACOSX) && !defined(OS_ANDROID)
   RunLoopbackProbeJob();
 #endif
   AbortAllInProgressJobs();
   // |this| may be deleted inside AbortAllInProgressJobs().
 }
 
 void HostResolverImpl::OnConnectionTypeChanged(
@@ skipping 168 matching lines @@
   if (job_)
     job_->CancelRequest(this);
 }
 
 void HostResolverImpl::RequestImpl::ChangeRequestPriority(
     RequestPriority priority) {
   job_->ChangeRequestPriority(this, priority);
 }
 
 }  // namespace net