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

webrtc/p2p/base/p2ptransportchannel.cc

Index: webrtc/p2p/base/p2ptransportchannel.cc
diff --git a/webrtc/p2p/base/p2ptransportchannel.cc b/webrtc/p2p/base/p2ptransportchannel.cc
index f506126cef563f78eac4fb6a700e3c2053ffd4dc..77b4d10c9431c58e52160b71fa598a006a0b71c5 100644
--- a/webrtc/p2p/base/p2ptransportchannel.cc
+++ b/webrtc/p2p/base/p2ptransportchannel.cc
@@ -1374,6 +1374,11 @@ bool P2PTransportChannel::IsPingable(Connection* conn, int64_t now) {
     return false;
   }
 
+  // A failed connection will not be pinged.
+  if (conn->state() == Connection::STATE_FAILED) {
+    return false;
+  }
+
   // An never connected connection cannot be written to at all, so pinging is
   // out of the question. However, if it has become WRITABLE, it is in the
   // reconnecting state so ping is needed.