NQE: Plumb RTT and throughput estimates to the UI thread

chrome/browser/net/nqe/ui_network_quality_estimator_service.h

Index: chrome/browser/net/nqe/ui_network_quality_estimator_service.h
diff --git a/chrome/browser/net/nqe/ui_network_quality_estimator_service.h b/chrome/browser/net/nqe/ui_network_quality_estimator_service.h
index cf205e5ed5f08394cecdc4fee8feb037336c7228..dd098bb8e6ed579a2eb1539247045375d2c9232f 100644
--- a/chrome/browser/net/nqe/ui_network_quality_estimator_service.h
+++ b/chrome/browser/net/nqe/ui_network_quality_estimator_service.h
@@ -47,6 +47,20 @@ class UINetworkQualityEstimatorService
       net::NetworkQualityEstimator::EffectiveConnectionTypeObserver* observer)
       override;
 
+  // Must be called on the UI thread. |observer| will be notified on the UI
+  // thread.  |observer| would be notified of the changes in the HTTP RTT,
+  // transport RTT or throughput. |observer| would be notified of the current
+  // values in the next message pump.
+  void AddRTTAndThroughputEstimatesObserver(

[RyanSturm, 2017/03/10 19:16:44]

I would add these to NetworkQualityProvider interface.

[tbansal1, 2017/03/10 21:57:50]

Done.

+      net::NetworkQualityEstimator::RTTAndThroughputEstimatesObserver*
+          observer);
+
+  // Removes |observer| from the list of RTT and throughput estimate observers.
+  // Must be called on the UI thread.
+  void RemoveRTTAndThroughputEstimatesObserver(
+      net::NetworkQualityEstimator::RTTAndThroughputEstimatesObserver*
+          observer);
+
   // Registers the profile-specific network quality estimator prefs.
   static void RegisterProfilePrefs(PrefRegistrySimple* registry);
 
@@ -72,6 +86,12 @@ class UINetworkQualityEstimatorService
       net::NetworkQualityEstimator::EffectiveConnectionTypeObserver* observer)
       const;
 
+  // Notifies |observer| of the current effective connection type if |observer|
+  // is still registered as an observer.
+  void NotifyRTTAndThroughputObserverIfPresent(
+      net::NetworkQualityEstimator::RTTAndThroughputEstimatesObserver* observer)
+      const;
+
   // KeyedService implementation:
   void Shutdown() override;
 
@@ -81,9 +101,20 @@ class UINetworkQualityEstimatorService
   // reported by NetworkchangeNotifier::GetConnectionType.
   void EffectiveConnectionTypeChanged(net::EffectiveConnectionType type);
 
+  // Called when the estimated HTTP RTT, estimated transport RTT or estimated
+  // downstream throughput is computed.
+  void RTTOrThroughputComputed(base::TimeDelta http_rtt,
+                               base::TimeDelta transport_rtt,
+                               int32_t downstream_throughput_kbps);
+
   // The current EffectiveConnectionType.
   net::EffectiveConnectionType type_;
 
+  // Current network quality metrics.
+  base::TimeDelta http_rtt_;
+  base::TimeDelta transport_rtt_;
+  int32_t downstream_throughput_kbps_;
+
   // IO thread based observer that is owned by this service. Created on the UI
   // thread, but used and deleted on the IO thread.
   std::unique_ptr<IONetworkQualityObserver> io_observer_;
@@ -93,6 +124,11 @@ class UINetworkQualityEstimatorService
       net::NetworkQualityEstimator::EffectiveConnectionTypeObserver>
       effective_connection_type_observer_list_;
 
+  // Observer list for changes in RTT or throughput values.
+  base::ObserverList<
+      net::NetworkQualityEstimator::RTTAndThroughputEstimatesObserver>
+      rtt_throughput_observer_list_;
+
   // Prefs manager that is owned by this service. Created on the UI thread, but
   // used and deleted on the IO thread.
   std::unique_ptr<net::NetworkQualitiesPrefsManager> prefs_manager_;