Adding a DataSavingsRecorder interface

components/data_reduction_proxy/core/common/data_savings_recorder.h

Index: components/data_reduction_proxy/core/common/data_savings_recorder.h
diff --git a/components/data_reduction_proxy/core/common/data_savings_recorder.h b/components/data_reduction_proxy/core/common/data_savings_recorder.h
new file mode 100644
index 0000000000000000000000000000000000000000..461f4173a98214c438e0c3aaa60e913a014eb7ee
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+++ b/components/data_reduction_proxy/core/common/data_savings_recorder.h
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+// Copyright 2016 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_REDUCTION_PROXY_CORE_COMMON_DATA_SAVINGS_RECORDER_H_
+#define COMPONENTS_DATA_REDUCTION_PROXY_CORE_COMMON_DATA_SAVINGS_RECORDER_H_
+
+#include <stdint.h>
+
+#include <string>
+
+namespace data_reduction_proxy {
+
+// An interface that will record data savings based on the amount of data used,
+// the original size of the data, and the request type.
+class DataSavingsRecorder {
+ public:
+  // Records detailed data usage. Assumes |data_used| is recorded already by
+  // previous handling of URLRequests. Also records daily data savings
+  // statistics to prefs and reports data savings UMA. |data_used| and
+  // |original_size| are measured in bytes.
+  virtual void UpdateDataSavings(const std::string& data_usage_host,
+                                 int64_t data_used,
+                                 int64_t original_size) = 0;
+};
+
+}  // namespace data_reduction_proxy
+
+#endif  // COMPONENTS_DATA_REDUCTION_PROXY_CORE_COMMON_DATA_SAVINGS_RECORDER_H_