chrome/browser/chrome_browser_field_trials_mobile.cc

   1 // Copyright 2013 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/chrome_browser_field_trials_mobile.h"
   6
   7 #include <string>
   8
   9 #include "base/command_line.h"
  10 #include "base/metrics/field_trial.h"
  11 #include "base/prefs/pref_service.h"
  12 #include "chrome/common/chrome_switches.h"
  13 #include "chrome/common/chrome_version_info.h"
  14
  15 namespace chrome {
  16
  17 namespace {
  18
  19 // Base function used by all data reduction proxy field trials. A trial is
  20 // only conducted for installs that are in the "Enabled" group. They are always
  21 // enabled on DEV and BETA channels, and for STABLE, a percentage will be
  22 // controlled from the server. Until the percentage is learned from the server,
  23 // a client-side configuration is used.
  24 void DataCompressionProxyBaseFieldTrial(
  25     const char* trial_name,
  26     const base::FieldTrial::Probability enabled_group_probability,
  27     const base::FieldTrial::Probability total_probability) {
  28   const char kEnabled[] = "Enabled";
  29   const char kDisabled[] = "Disabled";
  30
  31   // Find out if this is a stable channel.
  32   const bool kIsStableChannel =
  33       chrome::VersionInfo::GetChannel() == chrome::VersionInfo::CHANNEL_STABLE;
  34
  35   // Experiment enabled until Jan 1, 2015. By default, disabled.
  36   scoped_refptr<base::FieldTrial> trial(
  37       base::FieldTrialList::FactoryGetFieldTrial(
  38           trial_name,
  39           total_probability,
  40           kDisabled, 2015, 1, 1, base::FieldTrial::ONE_TIME_RANDOMIZED, NULL));
  41
  42   // Non-stable channels will run with probability 1.
  43   const int kEnabledGroup = trial->AppendGroup(
  44       kEnabled,
  45       kIsStableChannel ? enabled_group_probability : total_probability);
  46
  47   const int v = trial->group();
  48   VLOG(1) << trial_name <<  " enabled group id: " << kEnabledGroup
  49           << ". Selected group id: " << v;
  50 }
  51
  52 void DataCompressionProxyFieldTrials() {
  53   // Governs the rollout of the compression proxy for Chrome on mobile
  54   // platforms. In all channels, the percentage will be controlled from the
  55   // server, and is configured to be 100% = 1000 / 1000 until overridden by the
  56   // server.
  57   DataCompressionProxyBaseFieldTrial(
  58       "DataCompressionProxyRollout", 1000, 1000);
  59
  60   // Governs the rollout of the _promo_ for the compression proxy
  61   // independently from the rollout of compression proxy. The enabled
  62   // percentage is configured to be 10% = 100 / 1000 until overridden by the
  63   // server. When this trial is "Enabled," users get a promo, whereas
  64   // otherwise, compression is available without a promo.
  65   DataCompressionProxyBaseFieldTrial(
  66       "DataCompressionProxyPromoVisibility", 100, 1000);
  67 }
  68
  69 }  // namespace
  70
  71 void SetupMobileFieldTrials(const CommandLine& parsed_command_line,
  72                             const base::Time& install_time,
  73                             PrefService* local_state) {
  74   DataCompressionProxyFieldTrials();
  75 }
  76
  77 }  // namespace chrome