Record policy usage statistics every 24 hours.

chrome/browser/policy/policy_statistics_collector.h

Index: chrome/browser/policy/policy_statistics_collector.h
diff --git a/chrome/browser/policy/policy_statistics_collector.h b/chrome/browser/policy/policy_statistics_collector.h
new file mode 100644
index 0000000000000000000000000000000000000000..d97ce00cb2468778333921d42c8fbd766fe15c3a
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+++ b/chrome/browser/policy/policy_statistics_collector.h
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+// Copyright (c) 2012 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 CHROME_BROWSER_POLICY_POLICY_STATISTICS_COLLECTOR_H_
+#define CHROME_BROWSER_POLICY_POLICY_STATISTICS_COLLECTOR_H_
+
+#include "base/basictypes.h"
+#include "base/cancelable_callback.h"
+#include "base/memory/ref_counted.h"
+#include "base/time.h"
+
+class PrefService;
+
+namespace base {
+class TaskRunner;
+}
+
+namespace policy {
+
+class PolicyService;
+
+// Manages regular updates of policy usage UMA histograms.
+class PolicyStatisticsCollector {
+ public:
+  // Policy usage statistics update rate, in milliseconds.
+  static const int kStatisticsUpdateRate;
+
+  // Neither |policy_service| nor |prefs| can be NULL and must stay valid
+  // throughout the lifetime of PolicyStatisticsCollector.
+  PolicyStatisticsCollector(PolicyService* policy_service,
+                            PrefService* prefs,
+                            const scoped_refptr<base::TaskRunner>& task_runner);
+  virtual ~PolicyStatisticsCollector();
+
+  // Completes initialization and starts periodical statistic updates.
+  void Initialize();
+
+  static void RegisterPrefs(PrefService* prefs);
+
+ protected:
+  // protected virtual for mocking.
+  virtual void RecordPolicyUse(int id);
+
+ private:
+  void CollectStatistics();
+  void ScheduleUpdate(base::TimeDelta delay);
+
+  int max_policy_id_;
+
+  PolicyService* policy_service_;
+  PrefService* prefs_;
+
+  base::CancelableClosure update_callback_;
+
+  const scoped_refptr<base::TaskRunner> task_runner_;
+
+  DISALLOW_COPY_AND_ASSIGN(PolicyStatisticsCollector);
+};
+
+}  // namespace policy
+
+#endif  // CHROME_BROWSER_POLICY_POLICY_STATISTICS_COLLECTOR_H_