Adding non-tracking mode support to AddressTracker.

net/base/address_tracker_linux.h

Index: net/base/address_tracker_linux.h
diff --git a/net/base/address_tracker_linux.h b/net/base/address_tracker_linux.h
index 415e8c89e9d8dc354d48c8a48dc24064068f71fd..b092bf2148188a68c22cbeaf31fcd3db4c15a360 100644
--- a/net/base/address_tracker_linux.h
+++ b/net/base/address_tracker_linux.h
@@ -41,11 +41,14 @@ class NET_EXPORT_PRIVATE AddressTrackerLinux :
                       const base::Closure& tunnel_callback);
   virtual ~AddressTrackerLinux();
 
-  // Starts watching system configuration for changes. The current thread must
-  // have a MessageLoopForIO.
-  void Init();
+  // When |track| is true, it starts watching system configuration for
+  // changes. The current thread must have a
+  // MessageLoopForIO. Otherwise, the |AddressMap| and |online_links_|
+  // will be a one time snapshot of current system configuration.
+  void Init(bool track);
 
   AddressMap GetAddressMap() const;
+  base::hash_set<int> GetOnlineLinks() const;
 
   // Implementation of NetworkChangeNotifierLinux::GetCurrentConnectionType().
   // Safe to call from any thread, but will block until Init() has completed.
@@ -105,6 +108,7 @@ class NET_EXPORT_PRIVATE AddressTrackerLinux :
   AddressMap address_map_;
 
   // Set of interface indices for links that are currently online.
+  mutable base::Lock online_links_lock_;
   base::hash_set<int> online_links_;
 
   base::Lock is_offline_lock_;