Create a histogram serialization mechanism in components/metrics

base/metrics/histogram_sample_chromeos.h

+// Copyright (c) 2014 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 BASE_METRICS_HISTOGRAM_SAMPLE_CHROMEOS_H
+#define BASE_METRICS_HISTOGRAM_SAMPLE_CHROMEOS_H
+
+#include <string>
+
+#include "base/base_export.h"
+#include "base/compiler_specific.h"
+#include "base/metrics/metric_sample_chromeos.h"
+
+namespace base {
+// Represents a single histogram sample.
+// This class is meant to be used to serialize and deserialize samples to send
+// them from chrome OS to chrome.
+class BASE_EXPORT HistogramSample : public MetricSample {
+ public:
+  HistogramSample(const std::string& name,
+                  int sample,
+                  int min,
+                  int max,
+                  int nbucket);
+  virtual ~HistogramSample();
+
+  int sample() const;
+  int min() const;
+  int max() const;
+  int nbucket() const;
+  // Returns the sample serialized on the format:
+  // histogram\0|name_| |sample_| |min_| |max_| |nbucket_|\0
+  virtual string ToString() const OVERRIDE;
+
+  // static
+  // Deserialize a histogram passed as a string.
+  // Returns a HistogramSample if the deserialization is successful, otherwise
+  // returns NULL.
+  static HistogramSample* ReadHistogram(
+      const std::string& serialized_histogram);
+
+ private:
+  int max_, min_, sample_, nbucket_;
+};
+}  // namespace base
+#endif  // BASE_METRICS_HISTOGRAM_SAMPLE_CHROMEOS_H