[feat] use original webrtc header defines

src/qos/link_capacity_estimator.h

@@ -0,0 +1,39 @@
+/*
+ *  Copyright 2018 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+#ifndef MODULES_CONGESTION_CONTROLLER_GOOG_CC_LINK_CAPACITY_ESTIMATOR_H_
+#define MODULES_CONGESTION_CONTROLLER_GOOG_CC_LINK_CAPACITY_ESTIMATOR_H_
+
+#include <optional>
+
+#include "api/units/data_rate.h"
+
+namespace webrtc {
+class LinkCapacityEstimator {
+ public:
+  LinkCapacityEstimator();
+  DataRate UpperBound() const;
+  DataRate LowerBound() const;
+  void Reset();
+  void OnOveruseDetected(DataRate acknowledged_rate);
+  void OnProbeRate(DataRate probe_rate);
+  bool has_estimate() const;
+  DataRate estimate() const;
+
+ private:
+  friend class GoogCcStatePrinter;
+  void Update(DataRate capacity_sample, double alpha);
+
+  double deviation_estimate_kbps() const;
+  std::optional<double> estimate_kbps_;
+  double deviation_kbps_ = 0.4;
+};
+}  // namespace webrtc
+
+#endif  // MODULES_CONGESTION_CONTROLLER_GOOG_CC_LINK_CAPACITY_ESTIMATOR_H_