Move Network Quality Estimator files to //net/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
deleted file mode 100644
index 0a386e9bed80524f4231c438a55ac3953f61c08e..0000000000000000000000000000000000000000
--- a/net/base/network_quality_estimator.h
+++ /dev/null
@@ -1,671 +0,0 @@
-// 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_ESTIMATOR_H_
-#define NET_BASE_NETWORK_QUALITY_ESTIMATOR_H_
-
-#include <stddef.h>
-#include <stdint.h>
-
-#include <deque>
-#include <map>
-#include <memory>
-#include <string>
-#include <tuple>
-
-#include "base/compiler_specific.h"
-#include "base/gtest_prod_util.h"
-#include "base/macros.h"
-#include "base/memory/ref_counted.h"
-#include "base/memory/weak_ptr.h"
-#include "base/observer_list.h"
-#include "base/threading/thread_checker.h"
-#include "base/time/time.h"
-#include "net/base/external_estimate_provider.h"
-#include "net/base/net_export.h"
-#include "net/base/network_change_notifier.h"
-#include "net/base/socket_performance_watcher_factory.h"
-
-namespace base {
-class SingleThreadTaskRunner;
-}  // namespace base
-
-namespace net {
-
-class URLRequest;
-
-// NetworkQualityEstimator provides network quality estimates (quality of the
-// full paths to all origins that have been connected to).
-// The estimates are based on the observed organic traffic.
-// A NetworkQualityEstimator instance is attached to URLRequestContexts and
-// observes the traffic of URLRequests spawned from the URLRequestContexts.
-// A single instance of NQE can be attached to multiple URLRequestContexts,
-// thereby increasing the single NQE instance's accuracy by providing more
-// observed traffic characteristics.
-class NET_EXPORT_PRIVATE NetworkQualityEstimator
-    : public NetworkChangeNotifier::ConnectionTypeObserver,
-      public ExternalEstimateProvider::UpdatedEstimateDelegate {
- public:
-  // EffectiveConnectionType is the connection type whose typical performance is
-  // most similar to the measured performance of the network in use. In many
-  // cases, the "effective" connection type and the actual type of connection in
-  // use are the same, but often a network connection performs significantly
-  // different, usually worse, from its expected capabilities.
-  // EffectiveConnectionType of a network is independent of if the current
-  // connection is metered or not. For example, an unmetered slow connection may
-  // have EFFECTIVE_CONNECTION_TYPE_SLOW_2G as its effective connection type.
-  enum EffectiveConnectionType {
-    // The connection types should be in increasing order of quality.
-    EFFECTIVE_CONNECTION_TYPE_UNKNOWN = 0,
-    EFFECTIVE_CONNECTION_TYPE_OFFLINE,
-    EFFECTIVE_CONNECTION_TYPE_SLOW_2G,
-    EFFECTIVE_CONNECTION_TYPE_2G,
-    EFFECTIVE_CONNECTION_TYPE_3G,
-    EFFECTIVE_CONNECTION_TYPE_4G,
-    EFFECTIVE_CONNECTION_TYPE_BROADBAND,
-    EFFECTIVE_CONNECTION_TYPE_LAST,
-  };
-
-  // On Android, a Java counterpart will be generated for this enum.
-  // GENERATED_JAVA_ENUM_PACKAGE: org.chromium.net
-  // GENERATED_JAVA_CLASS_NAME_OVERRIDE: NetworkQualityObservationSource
-  // GENERATED_JAVA_PREFIX_TO_STRIP:
-  enum ObservationSource {
-    // The observation was taken at the request layer, e.g., a round trip time
-    // is recorded as the time between the request being sent and the first byte
-    // being received.
-    URL_REQUEST,
-    // The observation is taken from TCP statistics maintained by the kernel.
-    TCP,
-    // The observation is taken at the QUIC layer.
-    QUIC,
-    // The observation is a previously cached estimate of the metric.
-    CACHED_ESTIMATE,
-    // The observation is derived from network connection information provided
-    // by the platform. For example, typical RTT and throughput values are used
-    // for a given type of network connection.
-    DEFAULT_FROM_PLATFORM,
-    // The observation came from a Chromium-external source.
-    EXTERNAL_ESTIMATE
-  };
-
-  // Observes measurements of round trip time.
-  class NET_EXPORT_PRIVATE RTTObserver {
-   public:
-    // Will be called when a new RTT observation is available. The round trip
-    // time is specified in milliseconds. The time when the observation was
-    // taken and the source of the observation are provided.
-    virtual void OnRTTObservation(int32_t rtt_ms,
-                                  const base::TimeTicks& timestamp,
-                                  ObservationSource source) = 0;
-
-   protected:
-    RTTObserver() {}
-    virtual ~RTTObserver() {}
-
-   private:
-    DISALLOW_COPY_AND_ASSIGN(RTTObserver);
-  };
-
-  // Observes measurements of throughput.
-  class NET_EXPORT_PRIVATE ThroughputObserver {
-   public:
-    // Will be called when a new throughput observation is available.
-    // Throughput is specified in kilobits per second.
-    virtual void OnThroughputObservation(int32_t throughput_kbps,
-                                         const base::TimeTicks& timestamp,
-                                         ObservationSource source) = 0;
-
-   protected:
-    ThroughputObserver() {}
-    virtual ~ThroughputObserver() {}
-
-   private:
-    DISALLOW_COPY_AND_ASSIGN(ThroughputObserver);
-  };
-
-  // Creates a new NetworkQualityEstimator.
-  // |variation_params| is the map containing all field trial parameters
-  // related to NetworkQualityEstimator field trial.
-  // |external_estimates_provider| may be NULL.
-  NetworkQualityEstimator(
-      std::unique_ptr<ExternalEstimateProvider> external_estimates_provider,
-      const std::map<std::string, std::string>& variation_params);
-
-  // Construct a NetworkQualityEstimator instance allowing for test
-  // configuration. Registers for network type change notifications so estimates
-  // can be kept network specific.
-  // |external_estimates_provider| may be NULL.
-  // |variation_params| is the map containing all field trial parameters for the
-  // network quality estimator field trial.
-  // |allow_local_host_requests_for_tests| should only be true when testing
-  // against local HTTP server and allows the requests to local host to be
-  // used for network quality estimation.
-  // |allow_smaller_responses_for_tests| should only be true when testing.
-  // Allows the responses smaller than |kMinTransferSizeInBytes| or shorter than
-  // |kMinRequestDurationMicroseconds| to be used for network quality
-  // estimation.
-  NetworkQualityEstimator(
-      std::unique_ptr<ExternalEstimateProvider> external_estimates_provider,
-      const std::map<std::string, std::string>& variation_params,
-      bool allow_local_host_requests_for_tests,
-      bool allow_smaller_responses_for_tests);
-
-  ~NetworkQualityEstimator() override;
-
-  // Returns the effective type of the current connection.
-  EffectiveConnectionType GetEffectiveConnectionType() const;
-
-  // Returns true if RTT is available and sets |rtt| to estimated RTT at the
-  // HTTP layer. Virtualized for testing. |rtt| should not be null. The RTT at
-  // the HTTP layer measures the time from when the request was sent (this
-  // happens after the connection is established) to the time when the response
-  // headers were received.
-  virtual bool GetURLRequestRTTEstimate(base::TimeDelta* rtt) const
-      WARN_UNUSED_RESULT;
-
-  // Returns true if downlink throughput is available and sets |kbps| to
-  // estimated downlink throughput (in kilobits per second).
-  // Virtualized for testing. |kbps| should not be null.
-  virtual bool GetDownlinkThroughputKbpsEstimate(int32_t* kbps) const;
-
-  // Notifies NetworkQualityEstimator that the response header of |request| has
-  // been received.
-  void NotifyHeadersReceived(const URLRequest& request);
-
-  // Notifies NetworkQualityEstimator that the response body of |request| has
-  // been received.
-  void NotifyRequestCompleted(const URLRequest& request);
-
-  // Returns true if median RTT at the HTTP layer is available and sets |rtt|
-  // to the median of RTT observations since |begin_timestamp|.
-  // Virtualized for testing. |rtt| should not be null. The RTT at the HTTP
-  // layer measures the time from when the request was sent (this happens after
-  // the connection is established) to the time when the response headers were
-  // received.
-  virtual bool GetRecentURLRequestRTTMedian(
-      const base::TimeTicks& begin_timestamp,
-      base::TimeDelta* rtt) const WARN_UNUSED_RESULT;
-
-  // Returns true if median downstream throughput is available and sets |kbps|
-  // to the median of downstream throughput (in kilobits per second)
-  // observations since |begin_timestamp|. Virtualized for testing. |kbps|
-  // should not be null.
-  virtual bool GetRecentMedianDownlinkThroughputKbps(
-      const base::TimeTicks& begin_timestamp,
-      int32_t* kbps) const WARN_UNUSED_RESULT;
-
-  // Adds |rtt_observer| to the list of round trip time observers. Must be
-  // called on the IO thread.
-  void AddRTTObserver(RTTObserver* rtt_observer);
-
-  // Removes |rtt_observer| from the list of round trip time observers if it
-  // is on the list of observers. Must be called on the IO thread.
-  void RemoveRTTObserver(RTTObserver* rtt_observer);
-
-  // Adds |throughput_observer| to the list of throughput observers. Must be
-  // called on the IO thread.
-  void AddThroughputObserver(ThroughputObserver* throughput_observer);
-
-  // Removes |throughput_observer| from the list of throughput observers if it
-  // is on the list of observers. Must be called on the IO thread.
-  void RemoveThroughputObserver(ThroughputObserver* throughput_observer);
-
-  SocketPerformanceWatcherFactory* GetSocketPerformanceWatcherFactory();
-
- protected:
-  // NetworkID is used to uniquely identify a network.
-  // For the purpose of network quality estimation and caching, a network is
-  // uniquely identified by a combination of |type| and
-  // |id|. This approach is unable to distinguish networks with
-  // same name (e.g., different Wi-Fi networks with same SSID).
-  // This is a protected member to expose it to tests.
-  struct NET_EXPORT_PRIVATE NetworkID {
-    NetworkID(NetworkChangeNotifier::ConnectionType type, const std::string& id)
-        : type(type), id(id) {}
-    NetworkID(const NetworkID& other) : type(other.type), id(other.id) {}
-    ~NetworkID() {}
-
-    NetworkID& operator=(const NetworkID& other) {
-      type = other.type;
-      id = other.id;
-      return *this;
-    }
-
-    // Overloaded because NetworkID is used as key in a map.
-    bool operator<(const NetworkID& other) const {
-      return std::tie(type, id) < std::tie(other.type, other.id);
-    }
-
-    // Connection type of the network.
-    NetworkChangeNotifier::ConnectionType type;
-
-    // Name of this network. This is set to:
-    // - Wi-Fi SSID if the device is connected to a Wi-Fi access point and the
-    //   SSID name is available, or
-    // - MCC/MNC code of the cellular carrier if the device is connected to a
-    //   cellular network, or
-    // - "Ethernet" in case the device is connected to ethernet.
-    // - An empty string in all other cases or if the network name is not
-    //   exposed by platform APIs.
-    std::string id;
-  };
-
-  // Returns true if the cached network quality estimate was successfully read.
-  bool ReadCachedNetworkQualityEstimate();
-
-  // NetworkChangeNotifier::ConnectionTypeObserver implementation:
-  void OnConnectionTypeChanged(
-      NetworkChangeNotifier::ConnectionType type) override;
-
-  // ExternalEstimateProvider::UpdatedEstimateObserver implementation.
-  void OnUpdatedEstimateAvailable() override;
-
-  // Return a string equivalent to |type|.
-  const char* GetNameForEffectiveConnectionType(
-      EffectiveConnectionType type) const;
-
- private:
-  FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest, StoreObservations);
-  FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest, TestAddObservation);
-  FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest, ObtainOperatingParams);
-  FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest, HalfLifeParam);
-  FRIEND_TEST_ALL_PREFIXES(URLRequestTestHTTP, NetworkQualityEstimator);
-  FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest,
-                           PercentileSameTimestamps);
-  FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest,
-                           PercentileDifferentTimestamps);
-  FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest, ComputedPercentiles);
-  FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest, TestCaching);
-  FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest,
-                           TestLRUCacheMaximumSize);
-  FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest, TestGetMedianRTTSince);
-  FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest,
-                           TestExternalEstimateProviderMergeEstimates);
-
-  class SocketWatcher;
-  class SocketWatcherFactory;
-
-  // NetworkQuality is used to cache the quality of a network connection.
-  class NET_EXPORT_PRIVATE NetworkQuality {
-   public:
-    NetworkQuality();
-    // |rtt| is the estimate of the round trip time.
-    // |downstream_throughput_kbps| is the estimate of the downstream
-    // throughput in kilobits per second.
-    NetworkQuality(const base::TimeDelta& rtt,
-                   int32_t downstream_throughput_kbps);
-    NetworkQuality(const NetworkQuality& other);
-    ~NetworkQuality();
-
-    NetworkQuality& operator=(const NetworkQuality& other);
-
-    // Returns the estimate of the round trip time.
-    const base::TimeDelta& rtt() const { return rtt_; }
-
-    // Returns the estimate of the downstream throughput in Kbps (Kilobits per
-    // second).
-    int32_t downstream_throughput_kbps() const {
-      return downstream_throughput_kbps_;
-    }
-
-   private:
-    // Estimated round trip time.
-    base::TimeDelta rtt_;
-
-    // Estimated downstream throughput in kilobits per second.
-    int32_t downstream_throughput_kbps_;
-  };
-
-  // CachedNetworkQuality stores the quality of a previously seen network.
-  class NET_EXPORT_PRIVATE CachedNetworkQuality {
-   public:
-    explicit CachedNetworkQuality(const NetworkQuality& network_quality);
-    CachedNetworkQuality(const CachedNetworkQuality& other);
-    ~CachedNetworkQuality();
-
-    // Returns the network quality associated with this cached entry.
-    const NetworkQuality& network_quality() const { return network_quality_; }
-
-    // Returns true if this cache entry was updated before
-    // |cached_network_quality|.
-    bool OlderThan(const CachedNetworkQuality& cached_network_quality) const;
-
-    // Time when this cache entry was last updated.
-    const base::TimeTicks last_update_time_;
-
-    // Quality of this cached network.
-    const NetworkQuality network_quality_;
-
-   private:
-    DISALLOW_ASSIGN(CachedNetworkQuality);
-  };
-
-  // Records observations of network quality metrics (such as round trip time
-  // or throughput), along with the time the observation was made. Observations
-  // can be made at several places in the network stack, thus the observation
-  // source is provided as well. ValueType must be numerical so that statistics
-  // such as median, average can be computed.
-  template <typename ValueType>
-  struct NET_EXPORT_PRIVATE Observation {
-    Observation(const ValueType& value,
-                base::TimeTicks timestamp,
-                ObservationSource source)
-        : value(value), timestamp(timestamp), source(source) {
-      DCHECK(!timestamp.is_null());
-    }
-    ~Observation() {}
-
-    // Value of the observation.
-    const ValueType value;
-
-    // Time when the observation was taken.
-    const base::TimeTicks timestamp;
-
-    // The source of the observation.
-    const ObservationSource source;
-  };
-
-  // Holds an observation and its weight.
-  template <typename ValueType>
-  struct NET_EXPORT_PRIVATE WeightedObservation {
-    WeightedObservation(ValueType value, double weight)
-        : value(value), weight(weight) {}
-    WeightedObservation(const WeightedObservation& other)
-        : WeightedObservation(other.value, other.weight) {}
-
-    WeightedObservation& operator=(const WeightedObservation& other) {
-      value = other.value;
-      weight = other.weight;
-      return *this;
-    }
-
-    // Required for sorting the samples in the ascending order of values.
-    bool operator<(const WeightedObservation& other) const {
-      return (value < other.value);
-    }
-
-    // Value of the sample.
-    ValueType value;
-
-    // Weight of the sample. This is computed based on how much time has passed
-    // since the sample was taken.
-    double weight;
-  };
-
-  // Stores observations sorted by time.
-  template <typename ValueType>
-  class NET_EXPORT_PRIVATE ObservationBuffer {
-   public:
-    explicit ObservationBuffer(double weight_multiplier_per_second);
-    ~ObservationBuffer();
-
-    // Adds |observation| to the buffer. The oldest observation in the buffer
-    // will be evicted to make room if the buffer is already full.
-    void AddObservation(const Observation<ValueType>& observation) {
-      DCHECK_LE(observations_.size(),
-                static_cast<size_t>(kMaximumObservationsBufferSize));
-      // Evict the oldest element if the buffer is already full.
-      if (observations_.size() == kMaximumObservationsBufferSize)
-        observations_.pop_front();
-
-      observations_.push_back(observation);
-      DCHECK_LE(observations_.size(),
-                static_cast<size_t>(kMaximumObservationsBufferSize));
-    }
-
-    // Clears the observations stored in this buffer.
-    void Clear() { observations_.clear(); }
-
-    // Returns true iff the |percentile| value of the observations in this
-    // buffer is available. Sets |result| to the computed |percentile|
-    // value among all observations since |begin_timestamp|. If the value is
-    // unavailable, false is returned and |result| is not modified. Percentile
-    // value is unavailable if all the values in observation buffer are older
-    // than |begin_timestamp|. |result| must not be null.
-    // |disallowed_observation_sources| is the list of observation sources that
-    // should be excluded when computing the percentile.
-    bool GetPercentile(
-        const base::TimeTicks& begin_timestamp,
-        ValueType* result,
-        int percentile,
-        const std::vector<ObservationSource>& disallowed_observation_sources)
-        const WARN_UNUSED_RESULT;
-
-   private:
-    FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest, HalfLifeParam);
-
-    // Computes the weighted observations and stores them in
-    // |weighted_observations| sorted by ascending |WeightedObservation.value|.
-    // Only the observations with timestamp later than |begin_timestamp| are
-    // considered. Also, sets |total_weight| to the total weight of all
-    // observations. Should be called only when there is at least one
-    // observation in the buffer. |disallowed_observation_sources| is the list
-    // of observation sources that should be excluded when computing the
-    // weighted observations.
-    void ComputeWeightedObservations(
-        const base::TimeTicks& begin_timestamp,
-        std::vector<WeightedObservation<ValueType>>& weighted_observations,
-        double* total_weight,
-        const std::vector<ObservationSource>& disallowed_observation_sources)
-        const;
-
-    // Holds observations sorted by time, with the oldest observation at the
-    // front of the queue.
-    std::deque<Observation<ValueType>> observations_;
-
-    // The factor by which the weight of an observation reduces every second.
-    // For example, if an observation is 6 seconds old, its weight would be:
-    //     weight_multiplier_per_second_ ^ 6
-    // Calculated from |kHalfLifeSeconds| by solving the following equation:
-    //     weight_multiplier_per_second_ ^ kHalfLifeSeconds = 0.5
-    const double weight_multiplier_per_second_;
-
-    DISALLOW_COPY_AND_ASSIGN(ObservationBuffer);
-  };
-
-  // Value of round trip time observations is in base::TimeDelta.
-  typedef net::NetworkQualityEstimator::Observation<base::TimeDelta>
-      RttObservation;
-  typedef net::NetworkQualityEstimator::ObservationBuffer<base::TimeDelta>
-      RttObservationBuffer;
-
-  // Value of throughput observations is in kilobits per second.
-  typedef net::NetworkQualityEstimator::Observation<int32_t>
-      ThroughputObservation;
-  typedef net::NetworkQualityEstimator::ObservationBuffer<int32_t>
-      ThroughputObservationBuffer;
-
-  // This does not use a unordered_map or hash_map for code simplicity (key just
-  // implements operator<, rather than hash and equality) and because the map is
-  // tiny.
-  typedef std::map<NetworkID, CachedNetworkQuality> CachedNetworkQualities;
-
-  // Throughput is set to |kInvalidThroughput| if a valid value is
-  // unavailable. Readers should discard throughput value if it is set to
-  // |kInvalidThroughput|.
-  static const int32_t kInvalidThroughput;
-
-  // Tiny transfer sizes may give inaccurate throughput results.
-  // Minimum size of the transfer over which the throughput is computed.
-  static const int kMinTransferSizeInBytes = 10000;
-
-  // Minimum duration (in microseconds) of the transfer over which the
-  // throughput is computed.
-  static const int kMinRequestDurationMicroseconds = 1000;
-
-  // Minimum valid value of the variation parameter that holds RTT (in
-  // milliseconds) values.
-  static const int kMinimumRTTVariationParameterMsec = 1;
-
-  // Minimum valid value of the variation parameter that holds throughput (in
-  // kilobits per second) values.
-  static const int kMinimumThroughputVariationParameterKbps = 1;
-
-  // Maximum size of the cache that holds network quality estimates.
-  // Smaller size may reduce the cache hit rate due to frequent evictions.
-  // Larger size may affect performance.
-  static const size_t kMaximumNetworkQualityCacheSize = 10;
-
-  // Maximum number of observations that can be held in the ObservationBuffer.
-  static const size_t kMaximumObservationsBufferSize = 300;
-
-  // Time duration (in milliseconds) after which the estimate provided by
-  // external estimate provider is considered stale.
-  static const int kExternalEstimateProviderFreshnessDurationMsec =
-      5 * 60 * 1000;
-
-  // Returns the RTT value to be used when the valid RTT is unavailable. Readers
-  // 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();
-
-  // Obtains operating parameters from the field trial parameters.
-  void ObtainOperatingParams(
-      const std::map<std::string, std::string>& variation_params);
-
-  // Obtains the model parameters for different effective connection types from
-  // the field trial parameters. For each effective connection type, a model
-  // (currently composed of a RTT threshold and a downlink throughput threshold)
-  // is provided by the field trial.
-  void ObtainEffectiveConnectionTypeModelParams(
-      const std::map<std::string, std::string>& variation_params);
-
-  // Adds the default median RTT and downstream throughput estimate for the
-  // current connection type to the observation buffer.
-  void AddDefaultEstimates();
-
-  // Returns an estimate of network quality at the specified |percentile|.
-  // |disallowed_observation_sources| is the list of observation sources that
-  // should be excluded when computing the percentile.
-  // Only the observations later than |begin_timestamp| are taken into account.
-  // |percentile| must be between 0 and 100 (both inclusive) with higher
-  // percentiles indicating less performant networks. For example, if
-  // |percentile| is 90, then the network is expected to be faster than the
-  // returned estimate with 0.9 probability. Similarly, network is expected to
-  // be slower than the returned estimate with 0.1 probability.
-  base::TimeDelta GetRTTEstimateInternal(
-      const std::vector<ObservationSource>& disallowed_observation_sources,
-      const base::TimeTicks& begin_timestamp,
-      int percentile) const;
-  int32_t GetDownlinkThroughputKbpsEstimateInternal(
-      const base::TimeTicks& begin_timestamp,
-      int percentile) const;
-
-  // Returns the current network ID checking by calling the platform APIs.
-  // Virtualized for testing.
-  virtual NetworkID GetCurrentNetworkID() const;
-
-  // Writes the estimated quality of the current network to the cache.
-  void CacheNetworkQualityEstimate();
-
-  void NotifyObserversOfRTT(const RttObservation& observation);
-
-  void NotifyObserversOfThroughput(const ThroughputObservation& observation);
-
-  // Records the UMA related to RTT.
-  void RecordRTTUMA(int32_t estimated_value_msec,
-                    int32_t actual_value_msec) const;
-
-  // Returns true only if |request| can be used for network quality estimation.
-  // Only the requests that go over network are considered to provide useful
-  // observations.
-  bool RequestProvidesUsefulObservations(const URLRequest& request) const;
-
-  // Values of external estimate provider status. This enum must remain
-  // synchronized with the enum of the same name in
-  // metrics/histograms/histograms.xml.
-  enum NQEExternalEstimateProviderStatus {
-    EXTERNAL_ESTIMATE_PROVIDER_STATUS_NOT_AVAILABLE,
-    EXTERNAL_ESTIMATE_PROVIDER_STATUS_AVAILABLE,
-    EXTERNAL_ESTIMATE_PROVIDER_STATUS_QUERIED,
-    EXTERNAL_ESTIMATE_PROVIDER_STATUS_QUERY_SUCCESSFUL,
-    EXTERNAL_ESTIMATE_PROVIDER_STATUS_CALLBACK,
-    EXTERNAL_ESTIMATE_PROVIDER_STATUS_RTT_AVAILABLE,
-    EXTERNAL_ESTIMATE_PROVIDER_STATUS_DOWNLINK_BANDWIDTH_AVAILABLE,
-    EXTERNAL_ESTIMATE_PROVIDER_STATUS_BOUNDARY
-  };
-
-  // Records the metrics related to external estimate provider.
-  void RecordExternalEstimateProviderMetrics(
-      NQEExternalEstimateProviderStatus status) const;
-
-  // Determines if the requests to local host can be used in estimating the
-  // network quality. Set to true only for tests.
-  const bool allow_localhost_requests_;
-
-  // Determines if the responses smaller than |kMinTransferSizeInBytes|
-  // or shorter than |kMinTransferSizeInBytes| can be used in estimating the
-  // network quality. Set to true only for tests.
-  const bool allow_small_responses_;
-
-  // The factor by which the weight of an observation reduces every second.
-  const double weight_multiplier_per_second_;
-
-  // Time when last connection change was observed.
-  base::TimeTicks last_connection_change_;
-
-  // ID of the current network.
-  NetworkID current_network_id_;
-
-  // Peak network quality (fastest round-trip-time (RTT) and highest
-  // downstream throughput) measured since last connectivity change. RTT is
-  // measured from time the request is sent until the first byte received.
-  // The accuracy is decreased by ignoring these factors:
-  // 1) Multiple URLRequests can occur concurrently.
-  // 2) Includes server processing time.
-  NetworkQuality peak_network_quality_;
-
-  // Cache that stores quality of previously seen networks.
-  CachedNetworkQualities cached_network_qualities_;
-
-  // Buffer that holds throughput observations (in kilobits per second) sorted
-  // by timestamp.
-  ThroughputObservationBuffer downstream_throughput_kbps_observations_;
-
-  // Buffer that holds RTT observations sorted by timestamp.
-  RttObservationBuffer rtt_observations_;
-
-  // Default network quality observations obtained from the network quality
-  // estimator field trial parameters. The observations are indexed by
-  // ConnectionType.
-  NetworkQuality
-      default_observations_[NetworkChangeNotifier::CONNECTION_LAST + 1];
-
-  // Thresholds for different effective connection types obtained from field
-  // trial variation params. These thresholds encode how different connection
-  // types behave in general. In future, complex encodings (e.g., curve
-  // fitting) may be used.
-  NetworkQuality connection_thresholds_[EFFECTIVE_CONNECTION_TYPE_LAST];
-
-  // Estimated network quality. Updated on mainframe requests.
-  NetworkQuality estimated_median_network_quality_;
-
-  // ExternalEstimateProvider that provides network quality using operating
-  // system APIs. May be NULL.
-  const std::unique_ptr<ExternalEstimateProvider> external_estimate_provider_;
-
-  // Observer lists for round trip times and throughput measurements.
-  base::ObserverList<RTTObserver> rtt_observer_list_;
-  base::ObserverList<ThroughputObserver> throughput_observer_list_;
-
-  std::unique_ptr<SocketPerformanceWatcherFactory> watcher_factory_;
-
-  base::ThreadChecker thread_checker_;
-
-  base::WeakPtrFactory<NetworkQualityEstimator> weak_ptr_factory_;
-
-  DISALLOW_COPY_AND_ASSIGN(NetworkQualityEstimator);
-};
-
-}  // namespace net
-
-#endif  // NET_BASE_NETWORK_QUALITY_ESTIMATOR_H_