Create a histogram serialization mechanism in components/metrics

base/metrics/chromeos_metrics.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_CHROMEOS_METRICS_H_
+# define BASE_METRICS_CHROMEOS_METRICS_H_
+
+#include <fcntl.h>

[achaulk, 2014/04/07 22:16:00]

Typically the style is to forward declare as much as possible instead of
#including in headers

+#include <list>
+
+#include "base/base_export.h"
+#include "base/files/file_path.h"
+#include "base/memory/scoped_vector.h"
+#include "base/metrics/crash_sample.h"
+#include "base/metrics/metric_sample.h"
+
+namespace base {
+class BASE_EXPORT ChromeOSMetrics {
+ public:
+  // static
+  static MetricSample* ReadMessage(int fd);

[achaulk, 2014/04/07 22:16:00]

Since everything is static, why not just have this be a namespace instead of a
class?

+  static MetricSample* ReadSample(int32_t message_size, uint8* buffer);
+  static void ReadMetricsFromFile(const std::string& filename,
+                                  ScopedVector<MetricSample>* metrics);
+  static int32_t FormatSample(int32_t buffer_size, char* buffer,
+                                            const char* format, ...);
+  static int32_t WriteChromeMessage(MetricSample* sample, int32_t buffer_size,
+                                    char* buffer);
+  static bool WriteMetricToFile(MetricSample* sample,
+                                const std::string& filename);
+ private:
+  static const int kMessageMaxLength = 1024;
+};
+}  // namespace base
+# endif  // BASE_METRICS_CHROMEOS_METRICS_H_