Add WiFi SSID getter to NetworkChangeNotifier.

net/base/network_change_notifier_linux.h

Index: net/base/network_change_notifier_linux.h
diff --git a/net/base/network_change_notifier_linux.h b/net/base/network_change_notifier_linux.h
index 5a0f6dff308afeca8d64b2fe21963a1e703086e0..c9af83633d549a793b9361f1d51a0bd28ad743dd 100644
--- a/net/base/network_change_notifier_linux.h
+++ b/net/base/network_change_notifier_linux.h
@@ -5,6 +5,8 @@
 #ifndef NET_BASE_NETWORK_CHANGE_NOTIFIER_LINUX_H_
 #define NET_BASE_NETWORK_CHANGE_NOTIFIER_LINUX_H_
 
+#include <string>
+
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
@@ -27,6 +29,7 @@ class NET_EXPORT_PRIVATE NetworkChangeNotifierLinux
 
   // NetworkChangeNotifier:
   ConnectionType GetCurrentConnectionType() const override;
+  std::string GetCurrentWiFiSSID() const override;
 
   const internal::AddressTrackerLinux* GetAddressTrackerInternal()
       const override;