Read NQE prefs to network quality store under all cases

net/nqe/network_quality_estimator_params.h

 // Copyright 2016 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_NQE_NETWORK_QUALITY_ESTIMATOR_PARAMS_H_
 #define NET_NQE_NETWORK_QUALITY_ESTIMATOR_PARAMS_H_
 
 #include <map>
 #include <string>
 
@@ skipping 55 matching lines @@
 // Returns true if the effective connection type has been determined via
 // variation parameters.
 bool forced_effective_connection_type_set(
     const std::map<std::string, std::string>& variation_params);
 
 // Returns the effective connection type that was configured by variation
 // parameters.
 EffectiveConnectionType forced_effective_connection_type(
     const std::map<std::string, std::string>& variation_params);
 
+// Returns true if reading from the persistent cache has been enabled via field
+// trial.
+bool persistent_cache_reading_enabled(
+    const std::map<std::string, std::string>& variation_params);
+
 }  // namespace internal
 
 }  // namespace nqe
 
 }  // namespace net
 
 #endif  // NET_NQE_NETWORK_QUALITY_ESTIMATOR_PARAMS_H_