Create a histogram serialization mechanism in components/metrics

components/metrics/crash_sample_chromeos.h

+// Copyright 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 COMPONENTS_METRICS_CHROMEOS_CRASH_SAMPLE_CHROMEOS_H

[Ben Chan, 2014/04/18 20:27:08]

nit: I believe the convention is 

  COMPONENTS_METRICS_CHROMEOS_CRASH_SAMPLE_CHROMEOS_H_

instead of

  COMPONENTS_METRICS_CHROMEOS_CRASH_SAMPLE_CHROMEOS_H

+#define COMPONENTS_METRICS_CHROMEOS_CRASH_SAMPLE_CHROMEOS_H
+
+#include <string>
+
+#include "base/base_export.h"
+#include "base/compiler_specific.h"
+#include "components/metrics/metric_sample_chromeos.h"
+
+namespace metrics {
+
+// Represents a crash event described by a simple name.
+class BASE_EXPORT CrashSample : public MetricSample {
+ public:
+  explicit CrashSample(const std::string& crashname);
+  virtual ~CrashSample();
+
+  // Produce a serialized version of the crash.

[Ben Chan, 2014/04/18 20:27:08]

nit: [OCD] the comments in this file and other files use singular and plural
form inconsistently, e.g. Return vs Returns.

+  // Format: crash\0|name_|\0
+  virtual std::string ToString() const OVERRIDE;
+
+  // Return a CrashSample object representing the serialized crash if possible.
+  // If the deserialization fails, returns NULL.
+  static CrashSample* ReadCrash(const std::string& crash_serialized);
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(CrashSample);
+};
+
+}  // namespace metrics
+
+#endif  // COMPONENTS_METRICS_CHROMEOS_CRASH_SAMPLE_CHROMEOS_H