chrome/browser/net/async_dns_field_trial.cc

   1 // Copyright (c) 2012 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 #include "chrome/browser/net/async_dns_field_trial.h"
   6
   7 #include "base/metrics/field_trial.h"
   8 #include "base/metrics/histogram.h"
   9 #include "base/strings/string_util.h"
  10 #include "build/build_config.h"
  11
  12 namespace chrome_browser_net {
  13
  14 namespace {
  15
  16 // Source of the default value of the async DNS pref; used in histograms.
  17 enum PrefDefaultSource {
  18   PLATFORM,
  19   FIELD_TRIAL,
  20   HARD_CODED_DEFAULT,
  21   MAX_PREF_DEFAULT_SOURCE
  22 };
  23
  24 // Source of the actual value of the async DNS pref; used in histograms.
  25 enum PrefSource {
  26   MANAGED_PREF,
  27   SUPERVISED_PREF,
  28   EXTENSION_PREF,
  29   COMMAND_LINE_PREF,
  30   USER_PREF,
  31   RECOMMENDED_PREF,
  32   DEFAULT_PREF,
  33   UNKNOWN_PREF,
  34   MAX_PREF_SOURCE
  35 };
  36
  37 void HistogramPrefDefaultSource(PrefDefaultSource source, bool enabled) {
  38   if (enabled) {
  39     UMA_HISTOGRAM_ENUMERATION("AsyncDNS.PrefDefaultSource_Enabled",
  40                               source,
  41                               MAX_PREF_DEFAULT_SOURCE);
  42   } else {
  43     UMA_HISTOGRAM_ENUMERATION("AsyncDNS.PrefDefaultSource_Disabled",
  44                               source,
  45                               MAX_PREF_DEFAULT_SOURCE);
  46   }
  47 }
  48
  49 void HistogramPrefSource(PrefSource source, bool enabled) {
  50   if (enabled) {
  51     UMA_HISTOGRAM_ENUMERATION("AsyncDNS.PrefSource_Enabled",
  52                               source,
  53                               MAX_PREF_SOURCE);
  54   } else {
  55     UMA_HISTOGRAM_ENUMERATION("AsyncDNS.PrefSource_Disabled",
  56                               source,
  57                               MAX_PREF_SOURCE);
  58   }
  59 }
  60
  61 }  // namespace
  62
  63 bool ConfigureAsyncDnsFieldTrial() {
  64 #if defined(OS_ANDROID) || defined(OS_IOS)
  65   // There is no DnsConfigService on those platforms so disable the field trial.
  66   HistogramPrefDefaultSource(PLATFORM, false);
  67   return false;
  68 #endif
  69
  70 #if defined(OS_CHROMEOS) || defined(OS_MACOSX)
  71   const bool kDefault = true;
  72 #else
  73   const bool kDefault = false;
  74 #endif
  75
  76   // Configure the AsyncDns field trial as follows:
  77   // groups AsyncDnsA and AsyncDnsB: return true,
  78   // groups SystemDnsA and SystemDnsB: return false,
  79   // otherwise (trial absent): return default.
  80   std::string group_name = base::FieldTrialList::FindFullName("AsyncDns");
  81   if (!group_name.empty()) {
  82     const bool enabled = base::StartsWith(group_name, "AsyncDns",
  83                                           base::CompareCase::INSENSITIVE_ASCII);
  84     HistogramPrefDefaultSource(FIELD_TRIAL, enabled);
  85     return enabled;
  86   }
  87   HistogramPrefDefaultSource(HARD_CODED_DEFAULT, kDefault);
  88   return kDefault;
  89 }
  90
  91 void LogAsyncDnsPrefSource(const PrefService::Preference* pref) {
  92   CHECK(pref);
  93
  94   const base::Value* value = pref->GetValue();
  95   CHECK(value);
  96
  97   bool enabled;
  98   bool got_value = value->GetAsBoolean(&enabled);
  99   CHECK(got_value);
 100
 101   if (pref->IsManaged())
 102     HistogramPrefSource(MANAGED_PREF, enabled);
 103   else if (pref->IsExtensionControlled())
 104     HistogramPrefSource(EXTENSION_PREF, enabled);
 105   else if (pref->IsUserControlled())
 106     HistogramPrefSource(USER_PREF, enabled);
 107   else if (pref->IsDefaultValue())
 108     HistogramPrefSource(DEFAULT_PREF, enabled);
 109   else
 110     HistogramPrefSource(UNKNOWN_PREF, enabled);
 111 }
 112
 113 }  // namespace chrome_browser_net