Update from https://crrev.com/304418

net/quic/congestion_control/leaky_bucket.h

-// Copyright (c) 2012 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.
-//
-// Helper class to track the rate data can leave the buffer for pacing.
-// A leaky bucket drains the data at a constant rate regardless of fullness of
-// the buffer.
-// See http://en.wikipedia.org/wiki/Leaky_bucket for more details.
-
-#ifndef NET_QUIC_CONGESTION_CONTROL_LEAKY_BUCKET_H_
-#define NET_QUIC_CONGESTION_CONTROL_LEAKY_BUCKET_H_
-
-#include "base/basictypes.h"
-#include "net/base/net_export.h"
-#include "net/quic/quic_bandwidth.h"
-#include "net/quic/quic_protocol.h"
-#include "net/quic/quic_time.h"
-
-namespace net {
-
-class NET_EXPORT_PRIVATE LeakyBucket {
- public:
-  explicit LeakyBucket(QuicBandwidth draining_rate);
-
-  // Set the rate at which the bytes leave the buffer.
-  void SetDrainingRate(QuicTime now, QuicBandwidth draining_rate);
-
-  // Add data to the buffer.
-  void Add(QuicTime now, QuicByteCount bytes);
-
-  // Time until the buffer is empty.
-  QuicTime::Delta TimeRemaining(QuicTime now) const;
-
-  // Number of bytes in the buffer.
-  QuicByteCount BytesPending(QuicTime now);
-
- private:
-  void Update(QuicTime now);
-
-  QuicByteCount bytes_;
-  QuicTime time_last_updated_;
-  QuicBandwidth draining_rate_;
-
-  DISALLOW_COPY_AND_ASSIGN(LeakyBucket);
-};
-
-}  // namespace net
-
-#endif  // NET_QUIC_CONGESTION_CONTROL_LEAKY_BUCKET_H_