Create a histogram serialization mechanism in components/metrics

base/metrics/histogram_sample.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_H
+#define BASE_METRICS_HISTOGRAM_SAMPLE_H
+
+#include <string>
+
+#include "base/base_export.h"
+
+#include "base/metrics/metric_sample.h"
+
+namespace base {
+class BASE_EXPORT HistogramSample : public MetricSample {
+ public:
+  HistogramSample(const std::string& name,
+                  int sample,
+                  int min,
+                  int max,
+                  int nbucket);
+  virtual ~HistogramSample();
+  int sample();
+  int min();
+  int max();
+  int nbucket();
+  // static
+  static HistogramSample* ReadHistogram(
+      const std::string& serialized_histogram);
+  string toString() const;
+
+ protected:
+  int max_, min_, sample_, nbucket_;
+};
+}  // namespace base
+#endif  // BASE_METRICS_HISTOGRAM_SAMPLE_H