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

webrtc/p2p/base/stunrequest.h

Index: webrtc/p2p/base/stunrequest.h
diff --git a/webrtc/p2p/base/stunrequest.h b/webrtc/p2p/base/stunrequest.h
index 44c1ebff564ed825dd852bfc340b236cf261c43c..79d7ed8364f587593a482c18574b8ca3028cc961 100644
--- a/webrtc/p2p/base/stunrequest.h
+++ b/webrtc/p2p/base/stunrequest.h
@@ -39,6 +39,10 @@ class StunRequestManager {
   // Only for testing.
   void Flush(int msg_type);
 
+  // Returns true if at least one request with |msg_type| is scheduled for
+  // transmission. For testing only.
+  bool Exist(int msg_type);
+
   // Removes a stun request that was added previously.  This will happen
   // automatically when a request succeeds, fails, or times out.
   void Remove(StunRequest* request);