chromium/components/variations/variations_ids_provider.h

// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef COMPONENTS_VARIATIONS_VARIATIONS_IDS_PROVIDER_H_
#define COMPONENTS_VARIATIONS_VARIATIONS_IDS_PROVIDER_H_

#include <map>
#include <set>
#include <string>
#include <utility>
#include <vector>

#include "base/component_export.h"
#include "base/gtest_prod_util.h"
#include "base/memory/raw_ptr.h"
#include "base/metrics/field_trial.h"
#include "base/synchronization/lock.h"
#include "components/variations/proto/study.pb.h"
#include "components/variations/synthetic_trials.h"
#include "components/variations/variations.mojom.h"
#include "components/variations/variations_associated_data.h"

namespace variations {
class VariationsClient;

namespace cros_early_boot::evaluate_seed {
// For friend purposes (for DestroyInstanceForTesting().)
class VariationsCrosEvaluateSeedMainTest;
}  // namespace cros_early_boot::evaluate_seed

// The key for a VariationsIdsProvider's |variations_headers_map_|. A
// VariationsHeaderKey provides more details about the VariationsIDs included in
// a particular header. For example, the header associated with a key with true
// for |is_signed_in| and Study_GoogleWebVisibility_ANY for |web_visibility| has
// (i) VariationsIDs associated with external experiments, which can be sent
// only for signed-in users and (ii) VariationsIDs that can be sent in first-
// and third-party contexts.
struct COMPONENT_EXPORT(VARIATIONS) VariationsHeaderKey { … };

// A helper class for maintaining client experiments and metrics state
// transmitted in custom HTTP request headers.
// This class is a thread-safe singleton.
class COMPONENT_EXPORT(VARIATIONS) VariationsIdsProvider
    : public base::FieldTrialList::Observer,
      public SyntheticTrialObserver { … };

}  // namespace variations

#endif  // COMPONENTS_VARIATIONS_VARIATIONS_IDS_PROVIDER_H_