Notify NQE of TCP RTT values

net/base/network_quality_estimator.h

Index: net/base/network_quality_estimator.h
diff --git a/net/base/network_quality_estimator.h b/net/base/network_quality_estimator.h
index 9fa0ad1817604c0472f8e5bafb9f78b619cfe477..b847c95f6005c41c83f4edf5bac13fa402a66809 100644
--- a/net/base/network_quality_estimator.h
+++ b/net/base/network_quality_estimator.h
@@ -17,6 +17,7 @@
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "base/threading/thread_checker.h"
 #include "base/time/time.h"
@@ -28,6 +29,7 @@
 
 namespace net {
 
+class NetworkQualityEstimatorWatcherFactory;
 class URLRequest;
 
 // NetworkQualityEstimator provides network quality estimates (quality of the
@@ -40,8 +42,7 @@ class URLRequest;
 // observed traffic characteristics.
 class NET_EXPORT_PRIVATE NetworkQualityEstimator
     : public NetworkChangeNotifier::ConnectionTypeObserver,
-      public ExternalEstimateProvider::UpdatedEstimateDelegate,
-      public SocketPerformanceWatcherFactory {
+      public ExternalEstimateProvider::UpdatedEstimateDelegate {
  public:
   // On Android, a Java counterpart will be generated for this enum.
   // GENERATED_JAVA_ENUM_PACKAGE: org.chromium.net
@@ -161,12 +162,6 @@ class NET_EXPORT_PRIVATE NetworkQualityEstimator
       const base::TimeTicks& begin_timestamp,
       int32_t* kbps) const;
 
-  // SocketPerformanceWatcherFactory implementation:
-  scoped_ptr<SocketPerformanceWatcher> CreateSocketPerformanceWatcher(
-      const Protocol protocol) override;
-  void OnUpdatedRTTAvailable(const Protocol protocol,
-                             const base::TimeDelta& rtt) override;
-
   // Adds |rtt_observer| to the list of round trip time observers. Must be
   // called on the IO thread.
   void AddRTTObserver(RTTObserver* rtt_observer);
@@ -183,6 +178,9 @@ class NET_EXPORT_PRIVATE NetworkQualityEstimator
   // is on the list of observers. Must be called on the IO thread.
   void RemoveThroughputObserver(ThroughputObserver* throughput_observer);
 
+  // Virtualized for testing.
+  virtual SocketPerformanceWatcherFactory* GetSocketPerformanceWatcherFactory();
+
  protected:
   // NetworkID is used to uniquely identify a network.
   // For the purpose of network quality estimation and caching, a network is
@@ -231,7 +229,15 @@ class NET_EXPORT_PRIVATE NetworkQualityEstimator
   // ExternalEstimateProvider::UpdatedEstimateObserver implementation.
   void OnUpdatedEstimateAvailable() override;
 
+  // Called by |socket_performance_watcher_factory_| every time it receives a
+  // notification from a socket performance watcher.

[Ryan Sleevi, 2016/03/25 01:45:34]

This comment is leaking the abstraction details into the header; it's especially
at conflict with the comments on 180-182 (which implies a different factory can
be set, which may not call this method)

+  void OnUpdatedRTTAvailable(SocketPerformanceWatcherFactory::Protocol protocol,
+                             const base::TimeDelta& rtt);
+  void OnWatcherReset();
+
  private:
+  // Allows |NetworkQualityEstimatorWatcherFactory| to call protected functions.

[Ryan Sleevi, 2016/03/25 01:45:34]

You can drop this comment. Per
https://google.github.io/styleguide/cppguide.html#Implementation_Comments , this
is the "Do not state the obvious" aspect, as that's given to a reader who
understands C++ well.

+  friend class NetworkQualityEstimatorWatcherFactory;
   FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest, StoreObservations);
   FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest, TestKbpsRTTUpdates);
   FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest, TestAddObservation);
@@ -252,6 +258,7 @@ class NET_EXPORT_PRIVATE NetworkQualityEstimator
   FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest,
                            TestExternalEstimateProviderMergeEstimates);
   FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest, TestObservers);
+  FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest, TestTcpSocketRtt);
 
   // NetworkQuality is used to cache the quality of a network connection.
   class NET_EXPORT_PRIVATE NetworkQuality {
@@ -520,6 +527,9 @@ class NET_EXPORT_PRIVATE NetworkQualityEstimator
 
   void NotifyObserversOfThroughput(const ThroughputObservation& observation);
 
+  // For use by SocketPerformanceWatcher.
+  base::WeakPtr<NetworkQualityEstimator> GetWeakPtr();
+
   // Records the UMA related to RTT.
   void RecordRTTUMA(int32_t estimated_value_msec,
                     int32_t actual_value_msec) const;
@@ -595,8 +605,13 @@ class NET_EXPORT_PRIVATE NetworkQualityEstimator
   base::ObserverList<RTTObserver> rtt_observer_list_;
   base::ObserverList<ThroughputObserver> throughput_observer_list_;
 
+  scoped_ptr<SocketPerformanceWatcherFactory>
+      socket_performance_watcher_factory_;
+
   base::ThreadChecker thread_checker_;
 
+  base::WeakPtrFactory<NetworkQualityEstimator> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(NetworkQualityEstimator);
 };