Add SocketWatcherFactory as a helper class to NQE

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 32e1a3ef8a8b41672fed1eba59c03f43d94dec1a..35cbd1d80d3c57b269dcdcc195573b6bf439be2b 100644
--- a/net/base/network_quality_estimator.h
+++ b/net/base/network_quality_estimator.h
@@ -13,10 +13,12 @@
 #include <string>
 #include <tuple>
 
+#include "base/callback.h"
 #include "base/gtest_prod_util.h"
 #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"
@@ -26,6 +28,10 @@
 #include "net/base/socket_performance_watcher.h"
 #include "net/base/socket_performance_watcher_factory.h"
 
+namespace base {
+class SingleThreadTaskRunner;
+}  // namespace base
+
 namespace net {
 
 class URLRequest;
@@ -40,8 +46,7 @@ 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
@@ -168,12 +173,6 @@ 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);
@@ -190,6 +189,9 @@ 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
@@ -443,6 +445,39 @@ class NET_EXPORT_PRIVATE NetworkQualityEstimator
     DISALLOW_COPY_AND_ASSIGN(ObservationBuffer);
   };
 
+  typedef base::Callback<void(
+      SocketPerformanceWatcherFactory::Protocol protocol,
+      const base::TimeDelta& rtt)>
+      RTTUpdateCallback;
+
+  // SocketWatcherFactory implements SocketPerformanceWatcherFactory, and is
+  // owned by |NetworkQualityEstimator|. |SocketWatcherFactory| is thread safe.
+  class NET_EXPORT_PRIVATE SocketWatcherFactory
+      : public SocketPerformanceWatcherFactory {
+   public:
+    SocketWatcherFactory(
+        const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
+        RTTUpdateCallback rtt_update_callback);
+    ~SocketWatcherFactory() override;
+
+    // SocketPerformanceWatcherFactory implementation:
+    scoped_ptr<SocketPerformanceWatcher> CreateSocketPerformanceWatcher(
+        const Protocol protocol) override;
+    void OnUpdatedRTTAvailable(const Protocol protocol,
+                               const base::TimeDelta& rtt) override;
+    void OnWatcherReset() override;
+
+   private:
+    // TaskRunner on which the |rtt_update_callback_| is invoked.
+    scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
+
+    RTTUpdateCallback rtt_update_callback_;
+
+    base::WeakPtrFactory<SocketWatcherFactory> weak_ptr_factory_;
+
+    DISALLOW_COPY_AND_ASSIGN(SocketWatcherFactory);
+  };
+
   // Value of round trip time observations is in base::TimeDelta.
   typedef net::NetworkQualityEstimator::Observation<base::TimeDelta>
       RttObservation;
@@ -498,6 +533,10 @@ class NET_EXPORT_PRIVATE NetworkQualityEstimator
   // should discard RTT if it is set to the value returned by |InvalidRTT()|.
   static const base::TimeDelta InvalidRTT();
 
+  // Notifies |this| of a new transport layer RTT.
+  void OnUpdatedRTTAvailable(SocketPerformanceWatcherFactory::Protocol protocol,
+                             const base::TimeDelta& rtt);
+
   // Queries the external estimate provider for the latest network quality
   // estimates, and adds those estimates to the current observation buffer.
   void QueryExternalEstimateProvider();
@@ -535,6 +574,8 @@ class NET_EXPORT_PRIVATE NetworkQualityEstimator
 
   void NotifyObserversOfThroughput(const ThroughputObservation& observation);
 
+  base::WeakPtr<NetworkQualityEstimator> GetWeakPtr();
+
   // Records the UMA related to RTT.
   void RecordRTTUMA(int32_t estimated_value_msec,
                     int32_t actual_value_msec) const;
@@ -610,8 +651,12 @@ class NET_EXPORT_PRIVATE NetworkQualityEstimator
   base::ObserverList<RTTObserver> rtt_observer_list_;
   base::ObserverList<ThroughputObserver> throughput_observer_list_;
 
+  scoped_ptr<SocketPerformanceWatcherFactory> watcher_factory_;
+
   base::ThreadChecker thread_checker_;
 
+  base::WeakPtrFactory<NetworkQualityEstimator> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(NetworkQualityEstimator);
 };