NetworkChangeNotifierMac: lock access to network_reachable_ as it may be read

net/base/network_change_notifier_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_CHANGE_NOTIFIER_MAC_H_
 #define NET_BASE_NETWORK_CHANGE_NOTIFIER_MAC_H_
 #pragma once
 
 #include <SystemConfiguration/SCDynamicStore.h>
 #include <SystemConfiguration/SCNetworkReachability.h>
 
 #include "base/basictypes.h"
 #include "base/mac/scoped_cftyperef.h"
+#include "base/synchronization/lock.h"
 #include "net/base/network_change_notifier.h"
 #include "net/base/network_config_watcher_mac.h"
 
 namespace net {
 
 class NetworkChangeNotifierMac: public NetworkChangeNotifier {
  public:
   NetworkChangeNotifierMac();
   virtual ~NetworkChangeNotifierMac();
 
@@ skipping 27 matching lines @@
 
   static void ReachabilityCallback(SCNetworkReachabilityRef target,
                                    SCNetworkConnectionFlags flags,
                                    void* notifier);
 
   Forwarder forwarder_;
   const NetworkConfigWatcherMac config_watcher_;
   base::mac::ScopedCFTypeRef<CFRunLoopRef> run_loop_;
   base::mac::ScopedCFTypeRef<SCNetworkReachabilityRef> reachability_;
   bool network_reachable_;
+  mutable base::Lock network_reachable_lock_;
 
   DISALLOW_COPY_AND_ASSIGN(NetworkChangeNotifierMac);
 };
 
 }  // namespace net
 
 #endif  // NET_BASE_NETWORK_CHANGE_NOTIFIER_MAC_H_