Set the generation on peer reflexive candidates when created.

webrtc/p2p/base/port.cc

Index: webrtc/p2p/base/port.cc
diff --git a/webrtc/p2p/base/port.cc b/webrtc/p2p/base/port.cc
index c0e8d9770d8b11fb5e63b3c0221247d6eb2e7e82..6e26371daedd93620cfee32f7d58cc6fd68dbb47 100644
--- a/webrtc/p2p/base/port.cc
+++ b/webrtc/p2p/base/port.cc
@@ -1485,6 +1485,7 @@ void Connection::MaybeAddPrflxCandidate(ConnectionRequest* request,
   new_local_candidate.set_network_name(local_candidate().network_name());
   new_local_candidate.set_network_type(local_candidate().network_type());
   new_local_candidate.set_related_address(local_candidate().address());
+  new_local_candidate.set_generation(local_candidate().generation());
   new_local_candidate.set_foundation(ComputeFoundation(
       PRFLX_PORT_TYPE, local_candidate().protocol(),
       local_candidate().relay_protocol(), local_candidate().address()));