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diff --git a/third_party/libwebrtc/modules/rtp_rtcp/source/time_util.h b/third_party/libwebrtc/modules/rtp_rtcp/source/time_util.h
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+/*
+ *  Copyright (c) 2015 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_RTP_RTCP_SOURCE_TIME_UTIL_H_
+#define MODULES_RTP_RTCP_SOURCE_TIME_UTIL_H_
+
+#include <stdint.h>
+
+#include "api/units/time_delta.h"
+#include "rtc_base/numerics/safe_conversions.h"
+#include "system_wrappers/include/ntp_time.h"
+
+namespace webrtc {
+
+// Helper function for compact ntp representation:
+// RFC 3550, Section 4. Time Format.
+// Wallclock time is represented using the timestamp format of
+// the Network Time Protocol (NTP).
+// ...
+// In some fields where a more compact representation is
+// appropriate, only the middle 32 bits are used; that is, the low 16
+// bits of the integer part and the high 16 bits of the fractional part.
+inline uint32_t CompactNtp(NtpTime ntp) {
+  return (ntp.seconds() << 16) | (ntp.fractions() >> 16);
+}
+
+// Converts interval to compact ntp (1/2^16 seconds) resolution.
+// Negative values converted to 0, Overlarge values converted to max uint32_t.
+uint32_t SaturatedToCompactNtp(TimeDelta delta);
+
+// Convert interval to the NTP time resolution (1/2^32 seconds ~= 0.2 ns).
+// For deltas with absolute value larger than 35 minutes result is unspecified.
+inline constexpr int64_t ToNtpUnits(TimeDelta delta) {
+  // For better precision `delta` is taken with best TimeDelta precision (us),
+  // then multiplaction and conversion to seconds are swapped to avoid float
+  // arithmetic.
+  // 2^31 us ~= 35.8 minutes.
+  return (rtc::saturated_cast<int32_t>(delta.us()) * (int64_t{1} << 32)) /
+         1'000'000;
+}
+
+// Converts interval from compact ntp (1/2^16 seconds) resolution to TimeDelta.
+// This interval can be up to ~9.1 hours (2^15 seconds).
+// Values close to 2^16 seconds are considered negative and are converted to
+// minimum value of 1ms.
+TimeDelta CompactNtpRttToTimeDelta(uint32_t compact_ntp_interval);
+
+}  // namespace webrtc
+#endif  // MODULES_RTP_RTCP_SOURCE_TIME_UTIL_H_