Create a histogram serialization mechanism in components/metrics

components/metrics/export/linearhistogram_sample.cc

+// 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.
+
+#include "components/metrics/export/linearhistogram_sample.h"
+
+#include <string>
+#include <vector>
+
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/string_split.h"
+#include "base/strings/stringprintf.h"
+#include "components/metrics/export/metric_sample.h"
+
+using base::StringPrintf;
+using base::StringToInt;
+using base::SplitString;
+using std::string;
+using std::vector;
+
+namespace metrics {
+
+LinearHistogramSample::LinearHistogramSample(const std::string& histname,
+                                             int sample,
+                                             int max)
+    : MetricSample(MetricSample::LINEAR_HISTOGRAM, histname),
+      sample_(sample),
+      max_(max) {}
+
+LinearHistogramSample::~LinearHistogramSample() {}
+
+string LinearHistogramSample::ToString() const {
+  return StringPrintf(
+      "linearhistogram%c%s %d %d%c", '\0', name().c_str(), sample_, max_, '\0');
+}
+
+// static
+// Read a linear histogram from a string listing |name|, |sample|, |max|
+// separated by space.
+LinearHistogramSample* LinearHistogramSample::ReadLinearHistogram(
+    const std::string& histogram_serialized) {
+  vector<string> parts;
+  int sample, max;
+  SplitString(histogram_serialized, ' ', &parts);
+  if (parts.size() != 3) return NULL;
+  if (parts[0].length() == 0 || !StringToInt(parts[1], &sample) ||
+      !StringToInt(parts[2], &max))
+    return NULL;
+
+  return new LinearHistogramSample(parts[0], sample, max);
+}
+
+}  // namespace metrics