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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.
#include "chrome/browser/net/async_dns_field_trial.h"
#include "base/metrics/field_trial.h"
#include "base/metrics/histogram.h"
#include "base/strings/string_util.h"
#include "build/build_config.h"
namespace chrome_browser_net {
namespace {
// Source of the default value of the async DNS pref; used in histograms.
enum PrefDefaultSource {
PLATFORM,
FIELD_TRIAL,
HARD_CODED_DEFAULT,
MAX_PREF_DEFAULT_SOURCE
};
// Source of the actual value of the async DNS pref; used in histograms.
enum PrefSource {
MANAGED_PREF,
SUPERVISED_PREF,
EXTENSION_PREF,
COMMAND_LINE_PREF,
USER_PREF,
RECOMMENDED_PREF,
DEFAULT_PREF,
UNKNOWN_PREF,
MAX_PREF_SOURCE
};
void HistogramPrefDefaultSource(PrefDefaultSource source, bool enabled) {
if (enabled) {
UMA_HISTOGRAM_ENUMERATION("AsyncDNS.PrefDefaultSource_Enabled",
source,
MAX_PREF_DEFAULT_SOURCE);
} else {
UMA_HISTOGRAM_ENUMERATION("AsyncDNS.PrefDefaultSource_Disabled",
source,
MAX_PREF_DEFAULT_SOURCE);
}
}
void HistogramPrefSource(PrefSource source, bool enabled) {
if (enabled) {
UMA_HISTOGRAM_ENUMERATION("AsyncDNS.PrefSource_Enabled",
source,
MAX_PREF_SOURCE);
} else {
UMA_HISTOGRAM_ENUMERATION("AsyncDNS.PrefSource_Disabled",
source,
MAX_PREF_SOURCE);
}
}
} // namespace
bool ConfigureAsyncDnsFieldTrial() {
#if defined(OS_ANDROID) || defined(OS_IOS)
// There is no DnsConfigService on those platforms so disable the field trial.
HistogramPrefDefaultSource(PLATFORM, false);
return false;
#endif
#if defined(OS_CHROMEOS) || defined(OS_MACOSX)
const bool kDefault = true;
#else
const bool kDefault = false;
#endif
// Configure the AsyncDns field trial as follows:
// groups AsyncDnsA and AsyncDnsB: return true,
// groups SystemDnsA and SystemDnsB: return false,
// otherwise (trial absent): return default.
std::string group_name = base::FieldTrialList::FindFullName("AsyncDns");
if (!group_name.empty()) {
const bool enabled = base::StartsWith(group_name, "AsyncDns",
base::CompareCase::INSENSITIVE_ASCII);
HistogramPrefDefaultSource(FIELD_TRIAL, enabled);
return enabled;
}
HistogramPrefDefaultSource(HARD_CODED_DEFAULT, kDefault);
return kDefault;
}
void LogAsyncDnsPrefSource(const PrefService::Preference* pref) {
CHECK(pref);
const base::Value* value = pref->GetValue();
CHECK(value);
bool enabled;
bool got_value = value->GetAsBoolean(&enabled);
CHECK(got_value);
if (pref->IsManaged())
HistogramPrefSource(MANAGED_PREF, enabled);
else if (pref->IsExtensionControlled())
HistogramPrefSource(EXTENSION_PREF, enabled);
else if (pref->IsUserControlled())
HistogramPrefSource(USER_PREF, enabled);
else if (pref->IsDefaultValue())
HistogramPrefSource(DEFAULT_PREF, enabled);
else
HistogramPrefSource(UNKNOWN_PREF, enabled);
}
} // namespace chrome_browser_net
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