Revert of Implement THROTTLED priority semantics.

net/base/percentile_estimator.h

-// Copyright 2016 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_PERCENTILE_ESTIMATOR_H_
-#define NET_BASE_PERCENTILE_ESTIMATOR_H_
-
-#include "base/callback.h"
-#include "base/macros.h"
-#include "net/base/net_export.h"
-
-namespace net {
-
-// This class estimates statistical percentiles (e.g. 10%l, 50%l) for
-// integer distributions presented in stream form.  These estimates
-// adjust automatically when the stream distribution changes.
-// TODO(rdsmith): Expand the class to maintain floating point
-// estimates rather than integer estimates, when there's a use case
-// for that that deserves the extra complexity and pitfalls of
-// floating point arithmetic.
-class NET_EXPORT PercentileEstimator {
- public:
-  using RandomNumberCallback = base::Callback<int(void)>;
-
-  static const int kMedianPercentile = 50;
-
-  // |percentile| is a number between 0 and 100 indicating what percentile
-  // should be estimated (e.g. 50 would be a median estimate).
-  // |initial_estimate| is the value the class is seeded with; in other
-  // words, if AddSample() is never called,
-  // |CurrentEstimate() == initial_estimate|.
-  PercentileEstimator(int percentile, int initial_estimate);
-
-  ~PercentileEstimator();
-
-  int current_estimate() const { return current_estimate_; }
-  void AddSample(int sample);
-
-  // Specify a callback that will generate a "random" number
-  // in the range [0,99] on each call.  Used so that tests can
-  // rely on reproducible behavior.
-  void SetRandomNumberGeneratorForTesting(
-      RandomNumberCallback generator_callback);
-
- private:
-  const int percentile_;
-
-  bool sign_positive_;
-  int current_estimate_;
-  int current_step_;
-
-  RandomNumberCallback generator_callback_;
-
-  DISALLOW_COPY_AND_ASSIGN(PercentileEstimator);
-};
-
-}  // namespace net
-
-#endif  // NET_BASE_PERCENTILE_ESTIMATOR_H_