Change the default relay port from GTURN to TURN.

webrtc/p2p/client/basicportallocator.h

Index: webrtc/p2p/client/basicportallocator.h
diff --git a/webrtc/p2p/client/basicportallocator.h b/webrtc/p2p/client/basicportallocator.h
index 3044559a0bab2cf0d48248c6af4707516d832dce..b7ca0e509783dfdad8d119a444b276bdd060478f 100644
--- a/webrtc/p2p/client/basicportallocator.h
+++ b/webrtc/p2p/client/basicportallocator.h
@@ -30,6 +30,8 @@ class BasicPortAllocator : public PortAllocator {
   BasicPortAllocator(rtc::NetworkManager* network_manager,
                      rtc::PacketSocketFactory* socket_factory,
                      const ServerAddresses& stun_servers);
+  // TODO(honghaiz): Deprecate this constructor as it is only used by tests
+  // and downstream code that passes in empty arguments.
   BasicPortAllocator(rtc::NetworkManager* network_manager,
                      const ServerAddresses& stun_servers,
                      const rtc::SocketAddress& relay_server_udp,