Make NQE a derived class of NetworkQualityProvider

net/nqe/effective_connection_type_observer.h

Index: net/nqe/effective_connection_type_observer.h
diff --git a/net/nqe/effective_connection_type_observer.h b/net/nqe/effective_connection_type_observer.h
new file mode 100644
index 0000000000000000000000000000000000000000..ba42b33deaad88c5ebea814424f327a5452bc5a1
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+++ b/net/nqe/effective_connection_type_observer.h
@@ -0,0 +1,41 @@
+// 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_EFFECTIVE_CONNECTION_TYPE_OBSERVER_H_
+#define NET_NQE_NETWORK_QUALITY_EFFECTIVE_CONNECTION_TYPE_OBSERVER_H_
+
+#include "base/compiler_specific.h"
+#include "base/macros.h"
+#include "net/base/net_export.h"
+#include "net/nqe/effective_connection_type.h"
+
+namespace net {
+
+// Observes changes in effective connection type.
+class NET_EXPORT EffectiveConnectionTypeObserver {
+ public:
+  // Notifies the observer of a change in the effective connection type.
+  // NetworkQualityEstimator computes the effective connection type once in
+  // every interval of duration
+  // |effective_connection_type_recomputation_interval_|. Additionally, when
+  // there is a change in the connection type of the device, then the
+  // effective connection type is immediately recomputed.
+  //
+  // If the computed effective connection type is different from the
+  // previously notified effective connection type, then all the registered
+  // observers are notified of the new effective connection type.
+  virtual void OnEffectiveConnectionTypeChanged(
+      EffectiveConnectionType type) = 0;
+
+ protected:
+  EffectiveConnectionTypeObserver() {}
+  virtual ~EffectiveConnectionTypeObserver() {}
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(EffectiveConnectionTypeObserver);
+};
+
+}  // namespace net
+
+#endif  // NET_NQE_NETWORK_QUALITY_EFFECTIVE_CONNECTION_TYPE_OBSERVER_H_