[net] Use only DnsConfigService to detect DNS changes in HostResolverImpl

net/base/host_resolver_impl.h

 // 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.
 
 #ifndef NET_BASE_HOST_RESOLVER_IMPL_H_
 #define NET_BASE_HOST_RESOLVER_IMPL_H_
 
 #include <map>
 
 #include "base/basictypes.h"
@@ skipping 41 matching lines @@
 // from one thread!
 //
 // The HostResolverImpl enforces limits on the maximum number of concurrent
 // threads using PrioritizedDispatcher::Limits.
 //
 // Jobs are ordered in the queue based on their priority and order of arrival.
 class NET_EXPORT HostResolverImpl
     : public HostResolver,
       NON_EXPORTED_BASE(public base::NonThreadSafe),
       public NetworkChangeNotifier::IPAddressObserver,
-      public NetworkChangeNotifier::DNSObserver,
       public base::SupportsWeakPtr<HostResolverImpl> {
  public:
   // Parameters for ProcTask which resolves hostnames using HostResolveProc.
   //
   // |resolver_proc| is used to perform the actual resolves; it must be
   // thread-safe since it is run from multiple worker threads. If
   // |resolver_proc| is NULL then the default host resolver procedure is
   // used (which is SystemHostResolverProc except if overridden).
   //
   // For each attempt, we could start another attempt if host is not resolved
@@ skipping 139 matching lines @@
   // Might start new jobs.
   void AbortAllInProgressJobs();
 
   // Attempts to serve each Job in |jobs_| from the HOSTS file if we have
   // a DnsClient with a valid DnsConfig.
   void TryServingAllJobsFromHosts();
 
   // NetworkChangeNotifier::IPAddressObserver:
   virtual void OnIPAddressChanged() OVERRIDE;
 
-  // NetworkChangeNotifier::DNSObserver:
-  virtual void OnDNSChanged(unsigned detail) OVERRIDE;
-
   // DnsConfigService callback:
   void OnDnsConfigChanged(const DnsConfig& dns_config);
 
   // True if have a DnsClient with a valid DnsConfig.
   bool HaveDnsConfig() const;
 
   // Allows the tests to catch slots leaking out of the dispatcher.
   size_t num_running_jobs_for_tests() const {
     return dispatcher_.num_running_jobs();
   }
@@ skipping 36 matching lines @@
   HostResolverFlags additional_resolver_flags_;
 
   NetLog* net_log_;
 
   DISALLOW_COPY_AND_ASSIGN(HostResolverImpl);
 };
 
 }  // namespace net
 
 #endif  // NET_BASE_HOST_RESOLVER_IMPL_H_