use std::unordered_map and std::unordered_set in QUIC code instead of

net/quic/quic_packet_creator.cc

Index: net/quic/quic_packet_creator.cc
diff --git a/net/quic/quic_packet_creator.cc b/net/quic/quic_packet_creator.cc
index 794d6b2687f23de62f513dba37dd75907b043439..68ce339b9fcbb9b599131b0039decd6f2a33ac41 100644
--- a/net/quic/quic_packet_creator.cc
+++ b/net/quic/quic_packet_creator.cc
@@ -849,7 +849,7 @@ void QuicPacketCreator::SetCurrentPath(
                                   /*is_fec_timeout=*/false);
   // Save current packet number and load switching path's packet number.
   multipath_packet_number_[packet_.path_id] = packet_.packet_number;
-  hash_map<QuicPathId, QuicPacketNumber>::iterator it =
+  std::unordered_map<QuicPathId, QuicPacketNumber>::iterator it =
       multipath_packet_number_.find(path_id);
   // If path_id is not in the map, it's a new path. Set packet_number to 0.
   packet_.packet_number = it == multipath_packet_number_.end() ? 0 : it->second;