Use Android callback API to obtain cellular signal strength

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 14 matching lines @@
     const std::map<std::string, std::string>& variation_params);
 
 // Computes and returns the weight multiplier per second, which represents the
 // factor by which the weight of an observation reduces every second.
 // |variation_params| is the map containing all field trial parameters
 // related to the NetworkQualityualityEstimator field trial.
 double GetWeightMultiplierPerSecond(
     const std::map<std::string, std::string>& variation_params);
 
 // Returns the factor by which the weight of an observation reduces for every
-// dBm difference between the current signal strength (in dBm), and the signal
-// strength at the time when the observation was taken.
-double GetWeightMultiplierPerDbm(
+// signal strength level difference between the current signal strength, and
+// the signal strength at the time when the observation was taken.
+double GetWeightMultiplierPerSignalStrengthLevel(
     const std::map<std::string, std::string>& variation_params);
 
 // Returns a descriptive name corresponding to |connection_type|.
 const char* GetNameForConnectionType(
     net::NetworkChangeNotifier::ConnectionType connection_type);
 
 // Sets the default observation for different connection types in
 // |default_observations|. The default observations are different for different
 // connection types (e.g., 2G, 3G, 4G, WiFi). The default observations may be
 // used to determine the network quality in absence of any other information.
@@ skipping 35 matching lines @@
 base::TimeDelta GetMinSocketWatcherNotificationInterval(
     const std::map<std::string, std::string>& variation_params);
 
 }  // namespace internal
 
 }  // namespace nqe
 
 }  // namespace net
 
 #endif  // NET_NQE_NETWORK_QUALITY_ESTIMATOR_PARAMS_H_