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diff --git a/third_party/libwebrtc/call/receive_time_calculator.h b/third_party/libwebrtc/call/receive_time_calculator.h
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+++ b/third_party/libwebrtc/call/receive_time_calculator.h
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+/*
+ *  Copyright (c) 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 CALL_RECEIVE_TIME_CALCULATOR_H_
+#define CALL_RECEIVE_TIME_CALCULATOR_H_
+
+#include <stdint.h>
+
+#include <memory>
+
+#include "api/field_trials_view.h"
+#include "api/units/time_delta.h"
+#include "rtc_base/experiments/field_trial_parser.h"
+
+namespace webrtc {
+
+struct ReceiveTimeCalculatorConfig {
+  explicit ReceiveTimeCalculatorConfig(const FieldTrialsView& field_trials);
+  ReceiveTimeCalculatorConfig(const ReceiveTimeCalculatorConfig&);
+  ReceiveTimeCalculatorConfig& operator=(const ReceiveTimeCalculatorConfig&) =
+      default;
+  ~ReceiveTimeCalculatorConfig();
+  FieldTrialParameter<TimeDelta> max_packet_time_repair;
+  FieldTrialParameter<TimeDelta> stall_threshold;
+  FieldTrialParameter<TimeDelta> tolerance;
+  FieldTrialParameter<TimeDelta> max_stall;
+};
+
+// The receive time calculator serves the purpose of combining packet time
+// stamps with a safely incremental clock. This assumes that the packet time
+// stamps are based on lower layer timestamps that have more accurate time
+// increments since they are based on the exact receive time. They might
+// however, have large jumps due to clock resets in the system. To compensate
+// this they are combined with a safe clock source that is guaranteed to be
+// consistent, but it will not be able to measure the exact time when a packet
+// is received.
+class ReceiveTimeCalculator {
+ public:
+  static std::unique_ptr<ReceiveTimeCalculator> CreateFromFieldTrial(
+      const FieldTrialsView& field_trials);
+  explicit ReceiveTimeCalculator(const FieldTrialsView& field_trials);
+  int64_t ReconcileReceiveTimes(int64_t packet_time_us_,
+                                int64_t system_time_us_,
+                                int64_t safe_time_us_);
+
+ private:
+  int64_t last_corrected_time_us_ = -1;
+  int64_t last_packet_time_us_ = -1;
+  int64_t last_system_time_us_ = -1;
+  int64_t last_safe_time_us_ = -1;
+  int64_t total_system_time_passed_us_ = 0;
+  int64_t static_clock_offset_us_ = 0;
+  int64_t small_reset_during_stall_ = false;
+  ReceiveTimeCalculatorConfig config_;
+};
+}  // namespace webrtc
+#endif  // CALL_RECEIVE_TIME_CALCULATOR_H_