Update from https://crrev.com/309415

net/quic/crypto/cached_network_parameters.h

 // Copyright (c) 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef NET_QUIC_CRYPTO_CACHED_NETWORK_PARAMETERS_H_
 #define NET_QUIC_CRYPTO_CACHED_NETWORK_PARAMETERS_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 50 matching lines @@
   void set_max_bandwidth_timestamp_seconds(
       int64 max_bandwidth_timestamp_seconds) {
     max_bandwidth_timestamp_seconds_ = max_bandwidth_timestamp_seconds;
   }
 
   int32 min_rtt_ms() const {
     return min_rtt_ms_;
   }
   void set_min_rtt_ms(int32 min_rtt_ms) {
     min_rtt_ms_ = min_rtt_ms;
+    has_min_rtt_ms_ = true;
   }
+  bool has_min_rtt_ms() const { return has_min_rtt_ms_; }
 
   int32 previous_connection_state() const {
     return previous_connection_state_;
   }
   void set_previous_connection_state(int32 previous_connection_state) {
     previous_connection_state_ = previous_connection_state;
   }
 
   int64 timestamp() const { return timestamp_; }
   void set_timestamp(int64 timestamp) { timestamp_ = timestamp; }
 
  private:
   // serving_region_ is used to decide whether or not the bandwidth estimate and
   // min RTT are reasonable and if they should be used.
   // For example a group of geographically close servers may share the same
   // serving_region_ string if they are expected to have similar network
   // performance.
   std::string serving_region_;
   // The server can supply a bandwidth estimate (in bytes/s) which it may re-use
   // on receipt of a source-address token with this field set.
   int32 bandwidth_estimate_bytes_per_second_;
   // The maximum bandwidth seen by the client, not necessarily the latest.
   int32 max_bandwidth_estimate_bytes_per_second_;
   // Timestamp (seconds since UNIX epoch) that indicates when the max bandwidth
   // was seen by the server.
   int64 max_bandwidth_timestamp_seconds_;
   // The min RTT seen on a previous connection can be used by the server to
   // inform initial connection parameters for new connections.
   int32 min_rtt_ms_;
+  // Whenever min_rtt_ms_ is updated, it is set to true.
+  bool has_min_rtt_ms_;
   // Encodes the PreviousConnectionState enum.
   int32 previous_connection_state_;
   // UNIX timestamp when this bandwidth estimate was created.
   int64 timestamp_;
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_CRYPTO_CACHED_NETWORK_PARAMETERS_H_