blob: 0694ccf8086401aa0218c1ac73353b7c1ec940f6 [file] [log] [blame]
// Copyright 2016 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/variations/child_process_field_trial_syncer.h"
#include <set>
#include <utility>
#include "base/base_switches.h"
#include "base/command_line.h"
#include "components/variations/variations_crash_keys.h"
namespace variations {
ChildProcessFieldTrialSyncer::ChildProcessFieldTrialSyncer(
base::FieldTrialList::Observer* observer)
: observer_(observer) {}
ChildProcessFieldTrialSyncer::~ChildProcessFieldTrialSyncer() {}
void ChildProcessFieldTrialSyncer::InitFieldTrialObserving(
const base::CommandLine& command_line) {
// Set up initial set of crash dump data for field trials in this process.
variations::InitCrashKeys();
// Listen for field trial activations to report them to the browser.
base::FieldTrialList::AddObserver(observer_);
// Some field trials may have been activated before this point. Notify the
// browser of these activations now. To detect these, take the set difference
// of currently active trials with the initially active trials.
base::FieldTrial::ActiveGroups initially_active_trials;
base::FieldTrialList::GetInitiallyActiveFieldTrials(command_line,
&initially_active_trials);
std::set<std::string> initially_active_trials_set;
for (const auto& entry : initially_active_trials) {
initially_active_trials_set.insert(std::move(entry.trial_name));
}
base::FieldTrial::ActiveGroups current_active_trials;
base::FieldTrialList::GetActiveFieldTrialGroups(&current_active_trials);
for (const auto& trial : current_active_trials) {
if (!base::ContainsKey(initially_active_trials_set, trial.trial_name))
observer_->OnFieldTrialGroupFinalized(trial.trial_name, trial.group_name);
}
}
void ChildProcessFieldTrialSyncer::OnSetFieldTrialGroup(
const std::string& trial_name,
const std::string& group_name) {
base::FieldTrial* trial =
base::FieldTrialList::CreateFieldTrial(trial_name, group_name);
// Ensure the trial is marked as "used" by calling group() on it if it is
// marked as activated.
trial->group();
}
} // namespace variations