Do not delete a connection in the turn port with permission error or refresh error.

webrtc/p2p/base/port.h

Index: webrtc/p2p/base/port.h
diff --git a/webrtc/p2p/base/port.h b/webrtc/p2p/base/port.h
index 06efd2d3c235c4e976fda6f610c187741ac7542f..214b6bfeff7d2f012426b5ffa424b32e756c3428 100644
--- a/webrtc/p2p/base/port.h
+++ b/webrtc/p2p/base/port.h
@@ -523,6 +523,10 @@ class Connection : public CandidatePairInterface,
   // Makes the connection go away, in a failed state.
   void FailAndDestroy();
 
+  // Prunes the connection and sets its state to STATE_FAILED,
+  // It will not be used or pinged except that it can still receive packets.
+  void FailAndPrune();
+
   // Checks that the state of this connection is up-to-date.  The argument is
   // the current time, which is compared against various timeouts.
   void UpdateState(int64_t now);