Record NQE accuracy at main frame requests

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 2abc9fd7d6f7bffbcea10f7262ff497dbeb225c8..e2dc77ac108d45f98216a41afac78a193d349495 100644
--- a/net/nqe/network_quality_estimator.h
+++ b/net/nqe/network_quality_estimator.h
@@ -191,7 +191,8 @@ class NET_EXPORT_PRIVATE NetworkQualityEstimator
 
   // Returns true if the RTT is available and sets |rtt| to the RTT estimated at
   // the transport layer. |rtt| should not be null.
-  bool GetTransportRTTEstimate(base::TimeDelta* rtt) const WARN_UNUSED_RESULT;
+  virtual bool GetTransportRTTEstimate(base::TimeDelta* rtt) const

[bengr, 2016/06/01 16:55:29]

Add to the comment that this is virtualized for testing.

[tbansal1, 2016/06/01 21:49:02]

Done.

+      WARN_UNUSED_RESULT;
 
   // Returns true if downlink throughput is available and sets |kbps| to
   // estimated downlink throughput (in kilobits per second).
@@ -226,8 +227,8 @@ class NET_EXPORT_PRIVATE NetworkQualityEstimator
   // Returns true if the median RTT at the transport layer is available and sets
   // |rtt| to the median of transport layer RTT observations since
   // |start_time|. |rtt| should not be null.
-  bool GetRecentTransportRTTMedian(const base::TimeTicks& start_time,
-                                   base::TimeDelta* rtt) const
+  virtual bool GetRecentTransportRTTMedian(const base::TimeTicks& start_time,

[bengr, 2016/06/01 16:55:29]

Add to the comment that this is virtualized for testing.

[tbansal1, 2016/06/01 21:49:02]

Done.

+                                           base::TimeDelta* rtt) const
       WARN_UNUSED_RESULT;
 
   // Returns true if median downstream throughput is available and sets |kbps|
@@ -310,6 +311,11 @@ class NET_EXPORT_PRIVATE NetworkQualityEstimator
   const char* GetNameForEffectiveConnectionType(
       EffectiveConnectionType type) const;
 
+  // Virtualized for testing. Returns the list of intervals at which accuracy of

[bengr, 2016/06/01 16:55:30]

nits:
which -> which the
Move the first sentence to the end.

[tbansal1, 2016/06/01 21:49:02]

Done.

+  // network quality prediction should be recorded.
+  virtual const std::vector<base::TimeDelta>& GetAccuracyRecordingIntervals()
+      const;
+
   // Overrides the tick clock used by |this| for testing.
   void SetTickClockForTesting(std::unique_ptr<base::TickClock> tick_clock);
 
@@ -439,6 +445,13 @@ class NET_EXPORT_PRIVATE NetworkQualityEstimator
   // Notify observers of a change in effective connection type.
   void NotifyObserversOfEffectiveConnectionTypeChanged();
 
+  // Records NQE accuracy metrics. |measuring_duration| should belong to the
+  // vector returned by AccuracyRecordingIntervals().
+  // RecordAccuracyAfterMainFrame should be called |measuring_duration| after a
+  // main frame request is observed.
+  void RecordAccuracyAfterMainFrame(
+      const base::TimeDelta& measuring_duration) const;
+
   // Values of external estimate provider status. This enum must remain
   // synchronized with the enum of the same name in
   // metrics/histograms/histograms.xml.
@@ -479,6 +492,10 @@ class NET_EXPORT_PRIVATE NetworkQualityEstimator
   // 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_;
+
   // Time when last connection change was observed.
   base::TimeTicks last_connection_change_;
 
@@ -516,8 +533,11 @@ class NET_EXPORT_PRIVATE NetworkQualityEstimator
   nqe::internal::NetworkQuality
       connection_thresholds_[EFFECTIVE_CONNECTION_TYPE_LAST];
 
+  // Latest time when the headers for a main frame request were received.
+  base::TimeTicks last_main_frame_request_;
+
   // Estimated network quality. Updated on mainframe requests.
-  nqe::internal::NetworkQuality estimated_median_network_quality_;
+  nqe::internal::NetworkQuality estimated_quality_main_frame_;

[bengr, 2016/06/01 16:55:29]

estimated_quality_at_last_main_frame_request_? or
estimated_quality_at_last_main_frame_?

[tbansal1, 2016/06/01 21:49:02]

Done.

 
   // ExternalEstimateProvider that provides network quality using operating
   // system APIs. May be NULL.