Implement NetworkChangeNotifier::IsCurrentlyOffline() for Mac.

net/base/network_config_watcher_mac.h

 // Copyright (c) 2011 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_NETWORK_CONFIG_WATCHER_MAC_H_
 #define NET_BASE_NETWORK_CONFIG_WATCHER_MAC_H_
 
 #include <SystemConfiguration/SCDynamicStore.h>
 
 #include "base/basictypes.h"
@@ skipping 17 matching lines @@
     virtual ~Delegate() {}
 
     // Called to register the notification keys on |store|.
     // Implementors are expected to call SCDynamicStoreSetNotificationKeys().
     // Will be called on the notifier thread.
     virtual void SetDynamicStoreNotificationKeys(SCDynamicStoreRef store) = 0;
 
     // Called when one of the notification keys has changed.
     // Will be called on the notifier thread.
     virtual void OnNetworkConfigChange(CFArrayRef changed_keys) = 0;
+
+    // Called when the notifier thread is being destroyed.
+    // Will be called on the notifier thread.
+    virtual void CleanUp() {}
   };
 
   explicit NetworkConfigWatcherMac(Delegate* delegate);
   virtual ~NetworkConfigWatcherMac();
 
  private:
   // The thread used to listen for notifications.  This relays the notification
   // to the registered observers without posting back to the thread the object
   // was created on.
   scoped_ptr<base::Thread> notifier_thread_;
 
   DISALLOW_COPY_AND_ASSIGN(NetworkConfigWatcherMac);
 };
 
 }  // namespace net
 
 #endif  // NET_BASE_NETWORK_CONFIG_WATCHER_MAC_H_