Create a histogram serialization mechanism in components/metrics

base/metrics/linearhistogram_sample.cc

+// 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.
+
+#include <stdio.h>
+
+#include <string>
+
+#include "base/logging.h"
+#include "base/metrics/chromeos_metrics.h"
+#include "base/metrics/linearhistogram_sample.h"
+#include "base/metrics/metric_sample.h"
+#include "base/strings/stringprintf.h"
+
+using std::string;
+
+namespace base {
+LinearHistogramSample::LinearHistogramSample(const std::string& histname,
+                                             int sample,
+                                             int max)
+    : MetricSample(MetricSample::LINEAR_HISTOGRAM) {
+  name_ = histname;
+  sample_ = sample;
+  max_ = max;
+}
+
+int LinearHistogramSample::sample() { return sample_; }
+
+int LinearHistogramSample::max() { return max_; }
+
+LinearHistogramSample* LinearHistogramSample::ReadLinearHistogram(
+    const std::string& hist_repr) {
+  int sample, max;
+  char name[128];
+  int result = sscanf(hist_repr.c_str(), "%127s %d %d", name, &sample, &max);
+  if (result != 3) {
+    return NULL;
+  }
+  return new LinearHistogramSample(name, sample, max);
+}
+
+LinearHistogramSample::~LinearHistogramSample() {}
+
+string LinearHistogramSample::toString() const {
+  return StringPrintf(
+      "linearhistogram%c%s %d %d%c", '\0', name_.c_str(), sample_, max_, '\0');
+}
+}  // namespace base