Split SocketWatcher and SocketWatcherFactory out of NQE

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..d198cc10cecedb4ca31029651e765bff7dd0aefe 100644
--- a/net/nqe/network_quality_estimator.h
+++ b/net/nqe/network_quality_estimator.h
@@ -326,9 +326,6 @@ class NET_EXPORT_PRIVATE NetworkQualityEstimator
   FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest,
                            TestExternalEstimateProviderMergeEstimates);
 
-  class SocketWatcher;
-  class SocketWatcherFactory;
-
   // Value of round trip time observations is in base::TimeDelta.
   typedef nqe::internal::Observation<base::TimeDelta> RttObservation;
   typedef nqe::internal::ObservationBuffer<base::TimeDelta>