[net] Adds AddressTrackerLinux which keeps track of interface addresses using rtnetlink.

net/base/network_change_notifier_netlink_linux.h

Index: net/base/network_change_notifier_netlink_linux.h
diff --git a/net/base/network_change_notifier_netlink_linux.h b/net/base/network_change_notifier_netlink_linux.h
deleted file mode 100644
index 13abbc6c6047bc2b1e1a7d21d26d24558d31868c..0000000000000000000000000000000000000000
--- a/net/base/network_change_notifier_netlink_linux.h
+++ /dev/null
@@ -1,21 +0,0 @@
-// Copyright (c) 2010 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.
-
-// This file is to hide the netlink implementation details since the netlink.h
-// header contains a struct net; which conflicts with the net namespace.  So we
-// separate out all the netlink stuff into these files.
-
-#ifndef NET_BASE_NETWORK_CHANGE_NOTIFIER_NETLINK_LINUX_H_
-#define NET_BASE_NETWORK_CHANGE_NOTIFIER_NETLINK_LINUX_H_
-#pragma once
-
-#include <cstddef>
-
-// Returns the file descriptor if successful.  Otherwise, returns -1.
-int InitializeNetlinkSocket();
-
-// Returns true if a network change has been detected, otherwise returns false.
-bool HandleNetlinkMessage(char* buf, size_t len);
-
-#endif  // NET_BASE_NETWORK_CHANGE_NOTIFIER_NETLINK_LINUX_H_