chrome/browser/metrics/metrics_service_accessor.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CHROME_BROWSER_METRICS_METRICS_SERVICE_ACCESSOR_H_
   6 #define CHROME_BROWSER_METRICS_METRICS_SERVICE_ACCESSOR_H_
   7
   8 #include <stdint.h>
   9 #include <string>
  10
  11 #include "base/macros.h"
  12
  13 class MetricsService;
  14 class MetricsServiceObserver;
  15
  16 // This class limits and documents access to metrics service helper methods.
  17 // These methods are protected so each user has to inherit own program-specific
  18 // specialization and enable access there by declaring friends.
  19 class MetricsServiceAccessor {
  20  protected:
  21   // Constructor declared as protected to enable inheritance. Decendants should
  22   // disallow instantiation.
  23   MetricsServiceAccessor() {}
  24
  25   // Registers/unregisters |observer| to receive MetricsLog notifications
  26   // from metrics service.
  27   static void AddMetricsServiceObserver(MetricsServiceObserver* observer);
  28   static void RemoveMetricsServiceObserver(MetricsServiceObserver* observer);
  29
  30   // Registers the specified synthetic field trial (identified by a hash of the
  31   // trial name and group name) with |metrics_service|, if the service is not
  32   // NULL, returning true on success.
  33   // See the comment on MetricsService::RegisterSyntheticFieldTrial for details.
  34   static bool RegisterSyntheticFieldTrial(MetricsService* metrics_service,
  35                                           uint32_t trial_name_hash,
  36                                           uint32_t group_name_hash);
  37
  38  private:
  39   DISALLOW_COPY_AND_ASSIGN(MetricsServiceAccessor);
  40 };
  41
  42 #endif  // CHROME_BROWSER_METRICS_METRICS_SERVICE_ACCESSOR_H_