Create a histogram serialization mechanism in components/metrics

base/metrics/metric_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_METRIC_SAMPLE_H_
+#define BASE_METRICS_METRIC_SAMPLE_H_
+
+#include <string>
+
+#include "base/base_export.h"
+
+using std::string;
+
+namespace base {
+class BASE_EXPORT MetricSample {

[gauravsh, 2014/04/11 23:50:51]

I would think about adding comments for these classes, what it represents, when
to use it since these are being exported.

+ public:
+  enum SampleType {
+    CRASH,
+    HISTOGRAM,
+    LINEAR_HISTOGRAM,
+    SPARSE_HISTOGRAM,
+    USER_ACTION
+  };
+  explicit MetricSample(SampleType t);
+  virtual ~MetricSample();
+  virtual bool isValid() const;

[gauravsh, 2014/04/11 23:50:51]

NIT: newline before this.

[gauravsh, 2014/04/11 23:50:51]

function names (except accessors) start uppsercase. So IsValid() here and
ToString() below.

+  SampleType type();

[gauravsh, 2014/04/11 23:50:51]

This can be a const function.

+  string name() const;
+  virtual string toString() const;
+
+ protected:
+  SampleType type_;
+  string name_;
+};
+}  // namespace base
+#endif  // BASE_METRICS_METRIC_SAMPLE_H_