components/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 COMPONENTS_METRICS_METRICS_SERVICE_ACCESSOR_H_
   6 #define COMPONENTS_METRICS_METRICS_SERVICE_ACCESSOR_H_
   7
   8 #include <stdint.h>
   9
  10 #include "base/macros.h"
  11
  12 namespace metrics {
  13
  14 class MetricsService;
  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. Descendants should
  22   // disallow instantiation.
  23   MetricsServiceAccessor() {}
  24
  25   // Registers the specified synthetic field trial (identified by a hash of the
  26   // trial name and group name) with |metrics_service|, if the service is not
  27   // NULL, returning true on success.
  28   // See the comment on MetricsService::RegisterSyntheticFieldTrial for details.
  29   static bool RegisterSyntheticFieldTrial(
  30       MetricsService* metrics_service,
  31       uint32_t trial_name_hash,
  32       uint32_t group_name_hash);
  33
  34  private:
  35   DISALLOW_COPY_AND_ASSIGN(MetricsServiceAccessor);
  36 };
  37
  38 }  // namespace metrics
  39
  40 #endif  // COMPONENTS_METRICS_METRICS_SERVICE_ACCESSOR_H_