Keep on sending stun binding requests on zero-cost networks.

webrtc/base/network.h

Index: webrtc/base/network.h
diff --git a/webrtc/base/network.h b/webrtc/base/network.h
index a81bcabf660346f34d941a11494720b094084f58..680c005ea29ace284f9aae3c7bf4c07f9694f6a0 100644
--- a/webrtc/base/network.h
+++ b/webrtc/base/network.h
@@ -337,6 +337,8 @@ class Network {
   void set_ignored(bool ignored) { ignored_ = ignored; }
 
   AdapterType type() const { return type_; }
+  void set_type(AdapterType type) { type_ = type; }
+
   int preference() const { return preference_; }
   void set_preference(int preference) { preference_ = preference; }