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diff --git a/chromium/components/network_time/historical_latencies_container.h b/chromium/components/network_time/historical_latencies_container.h
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+++ b/chromium/components/network_time/historical_latencies_container.h
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+// Copyright 2022 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 COMPONENTS_NETWORK_TIME_HISTORICAL_LATENCIES_CONTAINER_H_
+#define COMPONENTS_NETWORK_TIME_HISTORICAL_LATENCIES_CONTAINER_H_
+
+#include "base/containers/ring_buffer.h"
+#include "base/time/time.h"
+#include "third_party/abseil-cpp/absl/types/optional.h"
+
+namespace network_time {
+
+// Number of historical latencies to record.
+constexpr int kMaxNumHistoricalLatencies = 16;
+
+// A class to record latencies of the previous `kNumHistoricalLatencies` time
+// fetches.
+class HistoricalLatenciesContainer {
+ public:
+  // Records a new latency in the container.
+  void Record(base::TimeDelta latency);
+
+  // Computes the standard deviation of the latest latencies. Returns nullopt
+  // if not enough latencies have been recorded yet.
+  absl::optional<base::TimeDelta> StdDeviation() const;
+
+ private:
+  base::RingBuffer<base::TimeDelta, size_t{kMaxNumHistoricalLatencies}>
+      latencies_;
+};
+
+}  // namespace network_time
+
+#endif  // COMPONENTS_NETWORK_TIME_HISTORICAL_LATENCIES_CONTAINER_H_