Make NQE a derived class of NetworkQualityProvider

net/nqe/network_quality_provider.h

Index: net/nqe/network_quality_provider.h
diff --git a/net/nqe/network_quality_provider.h b/net/nqe/network_quality_provider.h
new file mode 100644
index 0000000000000000000000000000000000000000..47eca719ba4426329dab034a098f2ee37af8505e
--- /dev/null
+++ b/net/nqe/network_quality_provider.h
@@ -0,0 +1,81 @@
+// Copyright 2017 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_NQE_NETWORK_QUALITY_PROVIDER_H_
+#define NET_NQE_NETWORK_QUALITY_PROVIDER_H_
+
+#include <stdint.h>
+
+#include "base/compiler_specific.h"
+#include "base/gtest_prod_util.h"
+#include "base/macros.h"
+#include "base/optional.h"
+#include "base/time/time.h"
+#include "net/base/net_export.h"
+#include "net/nqe/effective_connection_type.h"
+
+namespace net {
+
+class EffectiveConnectionTypeObserver;
+class RTTAndThroughputEstimatesObserver;
+
+// Provides simple interface to obtain the network quality, and to listen to
+// the changes in the network quality.
+class NET_EXPORT NetworkQualityProvider {
+ public:
+  virtual ~NetworkQualityProvider() {}
+
+  // Returns the current effective connection type.  The effective connection
+  // type is computed by the network quality estimator at regular intervals and
+  // at certain events (e.g., connection change).
+  virtual EffectiveConnectionType GetEffectiveConnectionType() const = 0;
+
+  // Adds |observer| to a list of effective connection type observers.
+  // The observer must register and unregister itself on the same thread.
+  // |observer| would be notified on the thread on which it registered.
+  // |observer| would be notified of the current effective connection
+  // type in the next message pump.
+  virtual void AddEffectiveConnectionTypeObserver(
+      EffectiveConnectionTypeObserver* observer) {}
+
+  // Removes |observer| from a list of effective connection type observers.
+  virtual void RemoveEffectiveConnectionTypeObserver(
+      EffectiveConnectionTypeObserver* observer) {}
+
+  // Returns the current HTTP RTT estimate. If the estimate is unavailable,
+  // the returned optional value is null.
+  virtual base::Optional<base::TimeDelta> GetHttpRTT() const;
+
+  // Returns the current transport RTT estimate. If the estimate is
+  // unavailable, the returned optional value is null.
+  virtual base::Optional<base::TimeDelta> GetTransportRTT() const;
+
+  // Returns the current downstream throughput estimate (in kilobits per
+  // second). If the estimate is unavailable, the returned optional value is
+  // null.
+  virtual base::Optional<int32_t> GetDownstreamThroughputKbps() const;
+
+  // Adds |observer| to the list of RTT and throughput estimate observers.
+  // The observer must register and unregister itself on the same thread.
+  // |observer| would be notified on the thread on which it registered.
+  // |observer| would be notified of the current values in the next message
+  // pump.
+  virtual void AddRTTAndThroughputEstimatesObserver(
+      RTTAndThroughputEstimatesObserver* observer) {}
+
+  // Removes |observer| from the list of RTT and throughput estimate
+  // observers.
+  virtual void RemoveRTTAndThroughputEstimatesObserver(
+      RTTAndThroughputEstimatesObserver* observer) {}
+
+ protected:
+  NetworkQualityProvider() {}
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(NetworkQualityProvider);
+};
+
+}  // namespace net
+
+#endif  // NET_NQE_NETWORK_QUALITY_PROVIDER_H_