Amortize data usage using TrafficStats on Android.

components/data_usage/core/data_use_amortizer.h

Index: components/data_usage/core/data_use_amortizer.h
diff --git a/components/data_usage/core/data_use_amortizer.h b/components/data_usage/core/data_use_amortizer.h
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+++ b/components/data_usage/core/data_use_amortizer.h
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+// Copyright 2015 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_DATA_USAGE_CORE_DATA_USE_AMORTIZER_H_
+#define COMPONENTS_DATA_USAGE_CORE_DATA_USE_AMORTIZER_H_
+
+#include <stdint.h>
+
+#include <vector>
+
+#include "components/data_usage/core/data_use.h"
+
+namespace data_usage {
+
+class DataUseAmortizer {
+ public:
+  virtual ~DataUseAmortizer() {}
+
+  // Amortize the given |data_use_sequence|, modifying the elements of
+  // |data_use_sequence| directly. |extra_tx_bytes| and |extra_rx_bytes| are
+  // the byte counts for data usage that is not included in |data_use_sequence|.
+  virtual void Amortize(std::vector<DataUse>* data_use_sequence,
+                        int64_t extra_tx_bytes,
+                        int64_t extra_rx_bytes) = 0;
+};
+
+}  // namespace data_usage
+
+#endif  // COMPONENTS_DATA_USAGE_CORE_DATA_USE_AMORTIZER_H_