Add a function to get Wifi SSID to net_util.

net/base/net_util_linux.h

Index: net/base/net_util_linux.h
diff --git a/net/base/net_util_linux.h b/net/base/net_util_linux.h
index fb5b6f44f9b563cf2af4758e2c6801ddd781000e..28d61af70a7cb2763e67b2bbc1d3b052c9e9618f 100644
--- a/net/base/net_util_linux.h
+++ b/net/base/net_util_linux.h
@@ -8,6 +8,8 @@
 // This file is only used to expose some of the internals
 // of net_util_linux.cc to address_tracker_linux and tests.
 
+#include <string>
+
 #include "base/containers/hash_tables.h"
 #include "net/base/address_tracker_linux.h"
 #include "net/base/net_util.h"
@@ -17,6 +19,8 @@ namespace internal {
 
 typedef char* (*GetInterfaceNameFunction)(int interface_index, char* ifname);
 
+typedef std::string (*GetInterfaceSSIDFunction)(const std::string& ifname);
+
 NET_EXPORT bool GetNetworkListImpl(
     NetworkInterfaceList* networks,
     int policy,
@@ -24,6 +28,10 @@ NET_EXPORT bool GetNetworkListImpl(
     const internal::AddressTrackerLinux::AddressMap& address_map,
     GetInterfaceNameFunction get_interface_name);
 
+NET_EXPORT std::string GetWifiSSIDFromInterfaceListInternal(
+    const NetworkInterfaceList& interfaces,
+    internal::GetInterfaceSSIDFunction get_interface_ssid);
+
 }  // namespace internal
 }  // namespace net