Add config to prune TURN ports

webrtc/p2p/base/p2ptransportchannel.h

Index: webrtc/p2p/base/p2ptransportchannel.h
diff --git a/webrtc/p2p/base/p2ptransportchannel.h b/webrtc/p2p/base/p2ptransportchannel.h
index d90cc61ebc7cd7058c5c9acad6765628319fba27..3d32f31565946509a5eeb21e033675c465e86c27 100644
--- a/webrtc/p2p/base/p2ptransportchannel.h
+++ b/webrtc/p2p/base/p2ptransportchannel.h
@@ -268,6 +268,9 @@ class P2PTransportChannel : public TransportChannelImpl,
   void AddConnection(Connection* connection);
 
   void OnPortReady(PortAllocatorSession *session, PortInterface* port);
+  void OnPortPruned(PortAllocatorSession* session, PortInterface* port);
+  // Returns true if the port is found and removed from |ports_|.
+  bool RemovePort(PortInterface* port);
   void OnCandidatesReady(PortAllocatorSession *session,
                          const std::vector<Candidate>& candidates);
   void OnCandidatesAllocationDone(PortAllocatorSession* session);