Compute effective connection type dynamically

net/nqe/network_quality_estimator.h

Index: net/nqe/network_quality_estimator.h
diff --git a/net/nqe/network_quality_estimator.h b/net/nqe/network_quality_estimator.h
index 0848eff0441ae3e7ae5b42c0842ec515e4ca150f..80c7feb6703eb7999e95c9db5e55583680abe5bb 100644
--- a/net/nqe/network_quality_estimator.h
+++ b/net/nqe/network_quality_estimator.h
@@ -287,6 +287,8 @@ class NET_EXPORT NetworkQualityEstimator
   virtual double RandDouble() const;
 
  private:
+  FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest,
+                           AdaptiveRecomputationEffectiveConnectionType);
   FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest, StoreObservations);
   FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest, TestAddObservation);
   FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest, ObtainOperatingParams);
@@ -297,6 +299,8 @@ class NET_EXPORT NetworkQualityEstimator
   FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest, TestGetMetricsSince);
   FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest,
                            TestExternalEstimateProviderMergeEstimates);
+  FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest,
+                           UnknownEffectiveConnectionType);
 
   // Value of round trip time observations is in base::TimeDelta.
   typedef nqe::internal::Observation<base::TimeDelta> RttObservation;
@@ -500,13 +504,6 @@ class NET_EXPORT NetworkQualityEstimator
   // Tick clock used by the network quality estimator.
   std::unique_ptr<base::TickClock> tick_clock_;
 
-  // Minimum duration between two consecutive computations of effective
-  // connection type. Set to non-zero value as a performance optimization.
-  const base::TimeDelta effective_connection_type_recomputation_interval_;
-
-  // Time when the effective connection type was last computed.
-  base::TimeTicks last_effective_connection_type_computation_;
-
   // Intervals after the main frame request arrives at which accuracy of network
   // quality prediction is recorded.
   std::vector<base::TimeDelta> accuracy_recording_intervals_;
@@ -583,6 +580,18 @@ class NET_EXPORT NetworkQualityEstimator
   // estimating the throughput.
   std::unique_ptr<nqe::internal::ThroughputAnalyzer> throughput_analyzer_;
 
+  // Minimum duration between two consecutive computations of effective
+  // connection type. Set to non-zero value as a performance optimization.
+  const base::TimeDelta effective_connection_type_recomputation_interval_;
+
+  // Time when the effective connection type was last computed.
+  base::TimeTicks last_effective_connection_type_computation_;
+
+  // Number of RTT and bandwidth samples available when effective connection
+  // type was last recomputed.
+  size_t rtt_observations_size_at_last_ect_computation_;
+  size_t throughput_observations_size_at_last_ect_computation_;
+
   // Current effective connection type. It is updated on connection change
   // events. It is also updated every time there is network traffic (provided
   // the last computation was more than