Store network quality samples so we can compute percentiles.

net/base/network_quality.h

 // Copyright 2015 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_BASE_NETWORK_QUALITY_H_
 #define NET_BASE_NETWORK_QUALITY_H_
 
 #include <stdint.h>
 
 #include "base/time/time.h"
+#include "net/base/net_export.h"
 
 namespace net {
 
 // API that is used to report the current network quality as estimated by the
 // NetworkQualityEstimator.
-struct NET_EXPORT_PRIVATE NetworkQuality {
-  NetworkQuality(const base::TimeDelta& fastest_rtt,
-                 double fastest_rtt_confidence,
-                 uint64_t peak_throughput_kbps,
-                 double peak_throughput_kbps_confidence)
-      : fastest_rtt(fastest_rtt),
-        fastest_rtt_confidence(fastest_rtt_confidence),
-        peak_throughput_kbps(peak_throughput_kbps),
-        peak_throughput_kbps_confidence(peak_throughput_kbps_confidence) {}
+class NET_EXPORT_PRIVATE NetworkQuality {
+ public:
+  // |rtt| is the estimate of the round trip time for the current connection.
+  // |rtt_confidence| is the confidence of the |rtt| estimate.
+  // |throughput_kbps| is the estimate of the Kbps for the current connection.
+  // |throughput_kbps_confidence| is the confidence of the |throughput_kbps|
+  // estimate.
+  NetworkQuality(const base::TimeDelta& rtt,
+                 double rtt_confidence,
+                 uint64_t throughput_kbps,

[bengr, 2015/06/05 20:44:13]

Be clear that this is downlink throuput.

[tbansal1, 2015/06/05 23:45:57]

Done.

+                 double throughput_kbps_confidence);

[bengr, 2015/06/05 20:44:13]

Follow the design and make this an enum, and don't separate RTT from throughput
confidence. 

[tbansal1, 2015/06/05 23:45:57]

Will do this in next CL, added TODO
Done

 
-  ~NetworkQuality() {}
+  ~NetworkQuality();
 
-  // The fastest round trip time observed for the current connection.
-  const base::TimeDelta fastest_rtt;
+  // Returns the round trip time observed for the current connection.
+  base::TimeDelta GetRtt() const;
 
-  // Confidence of the |fastest_rtt| estimate. Value lies between 0.0 and 1.0
+  // Returns the throughput in Kbps observed for the current connection.
+  uint64_t GetThroughputKbps() const;

[bengr, 2015/06/05 20:44:13]

GetDownlinkThroughputKbps?

Should this be an int32_t? I thought we were going to use int32s everywhere, and
that's why the units are kbps instead of bps.

[tbansal1, 2015/06/05 23:45:57]

Added TODO.

+
+ private:
+  // The round trip time observed for the current connection.
+  const base::TimeDelta rtt_;
+
+  // Confidence of the |rtt_| estimate. Value lies between 0.0 and 1.0
   // with 0.0 being no confidence and 1.0 implying that estimates are same as
   // ground truth.
   // TODO(tbansal): Define units so values intermediate between 0.0 and 1.0 are
   // meaningful.
-  const double fastest_rtt_confidence;
+  const double rtt_confidence_;

[bengr, 2015/06/05 20:44:13]

I would assign one confidence to the NetworkQuality object, not one per metric.
Too confusing.

Also, I'd use an enum.

[tbansal1, 2015/06/05 23:45:57]

Done.
Added TODO.

 
-  // Peak throughput in Kbps observed for the current connection.
-  const uint64_t peak_throughput_kbps;
+  // Throughput in Kbps observed for the current connection.
+  const uint64_t throughput_kbps_;
 
-  // Confidence of the |peak_throughput_kbps| estimate. Value lies between 0.0
+  // Confidence of the |throughput_kbps_| estimate. Value lies between 0.0
   // and 1.0 with 0.0 being no confidence and 1.0 implying that estimates are
   // same as ground truth.
   // TODO(tbansal): Define units so values intermediate between 0.0 and 1.0 are
   // meaningful.
-  const double peak_throughput_kbps_confidence;
+  const double throughput_kbps_confidence_;
 };
 
 }  // namespace net
 
 #endif  // NET_BASE_NETWORK_QUALITY_H_