[net] Move DnsConfigService to NetworkChangeNotifier.

net/dns/dns_config_service_posix.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_DNS_DNS_CONFIG_SERVICE_POSIX_H_
 #define NET_DNS_DNS_CONFIG_SERVICE_POSIX_H_
 
 #include <sys/types.h>
 #include <netinet/in.h>
 #include <resolv.h>
 
 #include "base/compiler_specific.h"
 #include "net/base/net_export.h"
 #include "net/dns/dns_config_service.h"
 
 namespace net {
 
-class SerialWorker;
-
 // Use DnsConfigService::CreateSystemService to use it outside of tests.
 namespace internal {
 
 class NET_EXPORT_PRIVATE DnsConfigServicePosix : public DnsConfigService {
  public:
   DnsConfigServicePosix();
   virtual ~DnsConfigServicePosix();
 
  private:
-  // NetworkChangeNotifier::DNSObserver:
-  virtual void OnDNSChanged(unsigned detail) OVERRIDE;
+  class Watcher;
+  class ConfigReader;
+  class HostsReader;
 
-  scoped_refptr<SerialWorker> config_reader_;
-  scoped_refptr<SerialWorker> hosts_reader_;
+  // DnsConfigService:
+  virtual void ReadNow() OVERRIDE;
+  virtual bool StartWatching() OVERRIDE;
+
+  void OnConfigChanged(bool succeeded);
+  void OnHostsChanged(bool succeeded);
+
+  scoped_ptr<Watcher> watcher_;
+  scoped_refptr<ConfigReader> config_reader_;
+  scoped_refptr<HostsReader> hosts_reader_;
 
   DISALLOW_COPY_AND_ASSIGN(DnsConfigServicePosix);
 };
 
 enum ConfigParsePosixResult {
   CONFIG_PARSE_POSIX_OK = 0,
   CONFIG_PARSE_POSIX_RES_INIT_FAILED,
   CONFIG_PARSE_POSIX_RES_INIT_UNSET,
   CONFIG_PARSE_POSIX_BAD_ADDRESS,
   CONFIG_PARSE_POSIX_BAD_EXT_STRUCT,
   CONFIG_PARSE_POSIX_NULL_ADDRESS,
   CONFIG_PARSE_POSIX_NO_NAMESERVERS,
   CONFIG_PARSE_POSIX_MISSING_OPTIONS,
   CONFIG_PARSE_POSIX_UNHANDLED_OPTIONS,
   CONFIG_PARSE_POSIX_MAX  // Bounding values for enumeration.
 };
 
 // Fills in |dns_config| from |res|.
 ConfigParsePosixResult NET_EXPORT_PRIVATE ConvertResStateToDnsConfig(
     const struct __res_state& res, DnsConfig* dns_config);
 
 }  // namespace internal
 
 }  // namespace net
 
 #endif  // NET_DNS_DNS_CONFIG_SERVICE_POSIX_H_