Extract ChromeBrowserFieldTrials out of ChromeBrowserMainParts.

chrome/browser/chrome_browser_main.cc

Index: chrome/browser/chrome_browser_main.cc
===================================================================
--- chrome/browser/chrome_browser_main.cc	(revision 148899)
+++ chrome/browser/chrome_browser_main.cc	(working copy)
@@ -23,8 +23,6 @@
 #include "base/string_number_conversions.h"
 #include "base/string_piece.h"
 #include "base/string_split.h"
-#include "base/string_util.h"
-#include "base/stringprintf.h"
 #include "base/sys_string_conversions.h"
 #include "base/threading/platform_thread.h"
 #include "base/time.h"
@@ -32,14 +30,11 @@
 #include "base/values.h"
 #include "build/build_config.h"
 #include "chrome/browser/about_flags.h"
-#include "chrome/browser/auto_launch_trial.h"
-#include "chrome/browser/autocomplete/autocomplete_field_trial.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/browser_process_impl.h"
 #include "chrome/browser/browser_shutdown.h"
 #include "chrome/browser/chrome_browser_main_extra_parts.h"
 #include "chrome/browser/defaults.h"
-#include "chrome/browser/extensions/default_apps_trial.h"
 #include "chrome/browser/extensions/extension_protocols.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/extensions_startup.h"
@@ -47,7 +42,6 @@
 #include "chrome/browser/google/google_search_counter.h"
 #include "chrome/browser/google/google_util.h"
 #include "chrome/browser/gpu_blacklist.h"
-#include "chrome/browser/gpu_util.h"
 #include "chrome/browser/jankometer.h"
 #include "chrome/browser/language_usage_metrics.h"
 #include "chrome/browser/managed_mode.h"
@@ -59,7 +53,6 @@
 #include "chrome/browser/metrics/variations_service.h"
 #include "chrome/browser/nacl_host/nacl_process_host.h"
 #include "chrome/browser/net/chrome_net_log.h"
-#include "chrome/browser/net/predictor.h"
 #include "chrome/browser/notifications/desktop_notification_service.h"
 #include "chrome/browser/notifications/desktop_notification_service_factory.h"
 #include "chrome/browser/page_cycler/page_cycler.h"
@@ -67,7 +60,6 @@
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/prefs/pref_value_store.h"
 #include "chrome/browser/prefs/scoped_user_pref_update.h"
-#include "chrome/browser/prerender/prerender_field_trial.h"
 #include "chrome/browser/printing/cloud_print/cloud_print_proxy_service.h"
 #include "chrome/browser/printing/cloud_print/cloud_print_proxy_service_factory.h"
 #include "chrome/browser/process_singleton.h"
@@ -93,7 +85,6 @@
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/chrome_result_codes.h"
 #include "chrome/common/chrome_switches.h"
-#include "chrome/common/chrome_version_info.h"
 #include "chrome/common/env_vars.h"
 #include "chrome/common/json_pref_store.h"
 #include "chrome/common/jstemplate_builder.h"
@@ -117,11 +108,7 @@
 #include "net/base/sdch_manager.h"
 #include "net/base/ssl_config_service.h"
 #include "net/cookies/cookie_monster.h"
-#include "net/http/http_basic_stream.h"
-#include "net/http/http_network_layer.h"
 #include "net/http/http_stream_factory.h"
-#include "net/socket/client_socket_pool_base.h"
-#include "net/socket/client_socket_pool_manager.h"
 #include "net/spdy/spdy_session.h"
 #include "net/spdy/spdy_session_pool.h"
 #include "net/url_request/url_request.h"
@@ -149,7 +136,6 @@
 #if defined(OS_WIN)
 #include "base/environment.h"  // For PreRead experiment.
 #include "base/win/windows_version.h"
-#include "chrome/browser/browser_trial.h"
 #include "chrome/browser/browser_util_win.h"
 #include "chrome/browser/chrome_browser_main_win.h"
 #include "chrome/browser/first_run/try_chrome_dialog_view.h"
@@ -437,16 +423,6 @@
 }
 #endif
 
-void SetSocketReusePolicy(int warmest_socket_trial_group,
-                          const int socket_policy[],
-                          int num_groups) {
-  const int* result = std::find(socket_policy, socket_policy + num_groups,
-                                warmest_socket_trial_group);
-  DCHECK_NE(result, socket_policy + num_groups)
-      << "Not a valid socket reuse policy group";
-  net::SetSocketReusePolicy(result - socket_policy);
-}
-
 // This code is specific to the Windows-only PreReadExperiment field-trial.
 void AddPreReadHistogramTime(const char* name, base::TimeDelta time) {
   const base::TimeDelta kMin(base::TimeDelta::FromMilliseconds(1));
@@ -498,53 +474,6 @@
           command_line.HasSwitch(switches::kImportFromFile));
 }
 
-// Set up a uniformity field trial. |one_time_randomized| indicates if the
-// field trial is one-time randomized or session-randomized. |trial_name_string|
-// must contain a "%d" since the percentage of the group will be inserted in
-// the trial name. |num_trial_groups| must be a divisor of 100 (e.g. 5, 20)
-void SetupSingleUniformityFieldTrial(
-    bool one_time_randomized,
-    const std::string& trial_name_string,
-    const chrome_variations::VariationID trial_base_id,
-    int num_trial_groups) {
-  // Probability per group remains constant for all uniformity trials, what
-  // changes is the probability divisor.
-  static const base::FieldTrial::Probability kProbabilityPerGroup = 1;
-  const std::string kDefaultGroupName = "default";
-  const base::FieldTrial::Probability divisor = num_trial_groups;
-
-  DCHECK_EQ(100 % num_trial_groups, 0);
-  const int group_percent = 100 / num_trial_groups;
-  const std::string trial_name = StringPrintf(trial_name_string.c_str(),
-                                              group_percent);
-
-  DVLOG(1) << "Trial name = " << trial_name;
-
-  scoped_refptr<base::FieldTrial> trial(
-      base::FieldTrialList::FactoryGetFieldTrial(
-          trial_name, divisor, kDefaultGroupName, 2015, 1, 1, NULL));
-  if (one_time_randomized)
-      trial->UseOneTimeRandomization();
-  experiments_helper::AssociateGoogleVariationID(trial_name, kDefaultGroupName,
-      trial_base_id);
-  // Loop starts with group 1 because the field trial automatically creates a
-  // default group, which would be group 0.
-  for (int group_number = 1; group_number < num_trial_groups; ++group_number) {
-    const std::string group_name = StringPrintf("group_%02d", group_number);
-    DVLOG(1) << "    Group name = " << group_name;
-    trial->AppendGroup(group_name, kProbabilityPerGroup);
-    experiments_helper::AssociateGoogleVariationID(trial_name, group_name,
-        static_cast<chrome_variations::VariationID>(trial_base_id +
-                                                    group_number));
-  }
-
-  // Now that all groups have been appended, call group() on the trial to
-  // ensure that our trial is registered. This resolves an off-by-one issue
-  // where the default group never gets chosen if we don't "use" the trial.
-  const int chosen_group = trial->group();
-  DVLOG(1) << "Chosen Group: " << chosen_group;
-}
-
 }  // namespace
 
 namespace chrome_browser {
@@ -568,6 +497,7 @@
       result_code_(content::RESULT_CODE_NORMAL_EXIT),
       startup_watcher_(new StartupTimeBomb()),
       shutdown_watcher_(new ShutdownWatcherHelper()),
+      browser_field_trials_(parameters.command_line),
       record_search_engine_(false),
       translate_manager_(NULL),
       profile_(NULL),
@@ -631,8 +561,8 @@
       browser_process_->variations_service();
   variations_service->CreateTrialsFromSeed(browser_process_->local_state());
 
-  SetupFieldTrials(local_state_->IsManagedPreference(
-                       prefs::kMaxConnectionsPerProxy));
+  browser_field_trials_.SetupFieldTrials(
+      local_state_->IsManagedPreference(prefs::kMaxConnectionsPerProxy));
 
   SetupPlatformFieldTrials();
 
@@ -643,507 +573,8 @@
   field_trial_synchronizer_ = new FieldTrialSynchronizer();
 }
 
-// This is an A/B test for the maximum number of persistent connections per
-// host. Currently Chrome, Firefox, and IE8 have this value set at 6. Safari
-// uses 4, and Fasterfox (a plugin for Firefox that supposedly configures it to
-// run faster) uses 8. We would like to see how much of an effect this value has
-// on browsing. Too large a value might cause us to run into SYN flood detection
-// mechanisms.
-void ChromeBrowserMainParts::ConnectionFieldTrial() {
-  const base::FieldTrial::Probability kConnectDivisor = 100;
-  const base::FieldTrial::Probability kConnectProbability = 1;  // 1% prob.
-
-  // This (6) is the current default value. Having this group declared here
-  // makes it straightforward to modify |kConnectProbability| such that the same
-  // probability value will be assigned to all the other groups, while
-  // preserving the remainder of the of probability space to the default value.
-  int connect_6 = -1;
-
-  // After June 30, 2011 builds, it will always be in default group.
-  scoped_refptr<base::FieldTrial> connect_trial(
-      base::FieldTrialList::FactoryGetFieldTrial(
-          "ConnCountImpact", kConnectDivisor, "conn_count_6", 2011, 6, 30,
-          &connect_6));
-
-  const int connect_5 = connect_trial->AppendGroup("conn_count_5",
-                                                   kConnectProbability);
-  const int connect_7 = connect_trial->AppendGroup("conn_count_7",
-                                                   kConnectProbability);
-  const int connect_8 = connect_trial->AppendGroup("conn_count_8",
-                                                   kConnectProbability);
-  const int connect_9 = connect_trial->AppendGroup("conn_count_9",
-                                                   kConnectProbability);
-
-  const int connect_trial_group = connect_trial->group();
-
-  int max_sockets = 0;
-  if (connect_trial_group == connect_5) {
-    max_sockets = 5;
-  } else if (connect_trial_group == connect_6) {
-    max_sockets = 6;
-  } else if (connect_trial_group == connect_7) {
-    max_sockets = 7;
-  } else if (connect_trial_group == connect_8) {
-    max_sockets = 8;
-  } else if (connect_trial_group == connect_9) {
-    max_sockets = 9;
-  } else {
-    NOTREACHED();
-  }
-  net::ClientSocketPoolManager::set_max_sockets_per_group(
-      net::HttpNetworkSession::NORMAL_SOCKET_POOL, max_sockets);
-}
-
-// A/B test for determining a value for unused socket timeout. Currently the
-// timeout defaults to 10 seconds. Having this value set too low won't allow us
-// to take advantage of idle sockets. Setting it to too high could possibly
-// result in more ERR_CONNECTION_RESETs, since some servers will kill a socket
-// before we time it out. Since these are "unused" sockets, we won't retry the
-// connection and instead show an error to the user. So we need to be
-// conservative here. We've seen that some servers will close the socket after
-// as short as 10 seconds. See http://crbug.com/84313 for more details.
-void ChromeBrowserMainParts::SocketTimeoutFieldTrial() {
-  const base::FieldTrial::Probability kIdleSocketTimeoutDivisor = 100;
-  // 1% probability for all experimental settings.
-  const base::FieldTrial::Probability kSocketTimeoutProbability = 1;
-
-  // After June 30, 2011 builds, it will always be in default group.
-  int socket_timeout_10 = -1;
-  scoped_refptr<base::FieldTrial> socket_timeout_trial(
-      base::FieldTrialList::FactoryGetFieldTrial(
-          "IdleSktToImpact", kIdleSocketTimeoutDivisor, "idle_timeout_10",
-          2011, 6, 30, &socket_timeout_10));
-
-  const int socket_timeout_5 =
-      socket_timeout_trial->AppendGroup("idle_timeout_5",
-                                        kSocketTimeoutProbability);
-  const int socket_timeout_20 =
-      socket_timeout_trial->AppendGroup("idle_timeout_20",
-                                        kSocketTimeoutProbability);
-
-  const int idle_to_trial_group = socket_timeout_trial->group();
-
-  if (idle_to_trial_group == socket_timeout_5) {
-    net::ClientSocketPool::set_unused_idle_socket_timeout(
-        base::TimeDelta::FromSeconds(5));
-  } else if (idle_to_trial_group == socket_timeout_10) {
-    net::ClientSocketPool::set_unused_idle_socket_timeout(
-        base::TimeDelta::FromSeconds(10));
-  } else if (idle_to_trial_group == socket_timeout_20) {
-    net::ClientSocketPool::set_unused_idle_socket_timeout(
-        base::TimeDelta::FromSeconds(20));
-  } else {
-    NOTREACHED();
-  }
-}
-
-void ChromeBrowserMainParts::ProxyConnectionsFieldTrial() {
-  const base::FieldTrial::Probability kProxyConnectionsDivisor = 100;
-  // 25% probability
-  const base::FieldTrial::Probability kProxyConnectionProbability = 1;
-
-  // This (32 connections per proxy server) is the current default value.
-  // Declaring it here allows us to easily re-assign the probability space while
-  // maintaining that the default group always has the remainder of the "share",
-  // which allows for cleaner and quicker changes down the line if needed.
-  int proxy_connections_32 = -1;
-
-  // After June 30, 2011 builds, it will always be in default group.
-  scoped_refptr<base::FieldTrial> proxy_connection_trial(
-      base::FieldTrialList::FactoryGetFieldTrial(
-          "ProxyConnectionImpact", kProxyConnectionsDivisor,
-          "proxy_connections_32", 2011, 6, 30, &proxy_connections_32));
-
-  // The number of max sockets per group cannot be greater than the max number
-  // of sockets per proxy server.  We tried using 8, and it can easily
-  // lead to total browser stalls.
-  const int proxy_connections_16 =
-      proxy_connection_trial->AppendGroup("proxy_connections_16",
-                                          kProxyConnectionProbability);
-  const int proxy_connections_64 =
-      proxy_connection_trial->AppendGroup("proxy_connections_64",
-                                          kProxyConnectionProbability);
-
-  const int proxy_connections_trial_group = proxy_connection_trial->group();
-
-  int max_sockets = 0;
-  if (proxy_connections_trial_group == proxy_connections_16) {
-    max_sockets = 16;
-  } else if (proxy_connections_trial_group == proxy_connections_32) {
-    max_sockets = 32;
-  } else if (proxy_connections_trial_group == proxy_connections_64) {
-    max_sockets = 64;
-  } else {
-    NOTREACHED();
-  }
-  net::ClientSocketPoolManager::set_max_sockets_per_proxy_server(
-      net::HttpNetworkSession::NORMAL_SOCKET_POOL, max_sockets);
-}
-
-// When --use-spdy not set, users will be in A/B test for spdy.
-// group A (npn_with_spdy): this means npn and spdy are enabled. In case server
-//                          supports spdy, browser will use spdy.
-// group B (npn_with_http): this means npn is enabled but spdy won't be used.
-//                          Http is still used for all requests.
-//           default group: no npn or spdy is involved. The "old" non-spdy
-//                          chrome behavior.
-void ChromeBrowserMainParts::SpdyFieldTrial() {
-  bool use_field_trial = true;
-  if (parsed_command_line().HasSwitch(switches::kUseSpdy)) {
-    std::string spdy_mode =
-        parsed_command_line().GetSwitchValueASCII(switches::kUseSpdy);
-    net::HttpNetworkLayer::EnableSpdy(spdy_mode);
-    use_field_trial = false;
-  }
-  if (parsed_command_line().HasSwitch(switches::kEnableSpdy3)) {
-    net::HttpStreamFactory::EnableNpnSpdy3();
-    use_field_trial = false;
-  } else if (parsed_command_line().HasSwitch(switches::kEnableNpn)) {
-    net::HttpStreamFactory::EnableNpnSpdy();
-    use_field_trial = false;
-  } else if (parsed_command_line().HasSwitch(switches::kEnableNpnHttpOnly)) {
-    net::HttpStreamFactory::EnableNpnHttpOnly();
-    use_field_trial = false;
-  }
-  if (use_field_trial) {
-    const base::FieldTrial::Probability kSpdyDivisor = 100;
-    // Enable SPDY/3 for 95% of the users, HTTP (no SPDY) for 1% of the users
-    // and SPDY/2 for 4% of the users.
-    base::FieldTrial::Probability npnhttp_probability = 1;
-    base::FieldTrial::Probability spdy3_probability = 95;
-
-#if defined(OS_CHROMEOS)
-    // Always enable SPDY (spdy/2 or spdy/3) on Chrome OS
-    npnhttp_probability = 0;
-#endif  // !defined(OS_CHROMEOS)
-
-    // NPN with spdy support is the default.
-    int npn_spdy_grp = -1;
-
-    // After June 30, 2013 builds, it will always be in default group.
-    scoped_refptr<base::FieldTrial> trial(
-        base::FieldTrialList::FactoryGetFieldTrial(
-            "SpdyImpact", kSpdyDivisor, "npn_with_spdy", 2013, 6, 30,
-            &npn_spdy_grp));
-
-    // NPN with only http support, no spdy.
-    int npn_http_grp = trial->AppendGroup("npn_with_http", npnhttp_probability);
-
-    // NPN with http/1.1, spdy/2, and spdy/3 support.
-    int spdy3_grp = trial->AppendGroup("spdy3", spdy3_probability);
-
-    int trial_grp = trial->group();
-    if (trial_grp == npn_spdy_grp) {
-      net::HttpStreamFactory::EnableNpnSpdy();
-    } else if (trial_grp == npn_http_grp) {
-      net::HttpStreamFactory::EnableNpnHttpOnly();
-    } else if (trial_grp == spdy3_grp) {
-      net::HttpStreamFactory::EnableNpnSpdy3();
-    } else {
-      NOTREACHED();
-    }
-  }
-
-  // Setup SPDY CWND Field trial.
-  const base::FieldTrial::Probability kSpdyCwndDivisor = 100;
-  const base::FieldTrial::Probability kSpdyCwnd16 = 20;     // fixed at 16
-  const base::FieldTrial::Probability kSpdyCwnd10 = 20;     // fixed at 10
-  const base::FieldTrial::Probability kSpdyCwndMin16 = 20;  // no less than 16
-  const base::FieldTrial::Probability kSpdyCwndMin10 = 20;  // no less than 10
-
-  // After June 30, 2013 builds, it will always be in default group
-  // (cwndDynamic).
-  scoped_refptr<base::FieldTrial> trial(
-      base::FieldTrialList::FactoryGetFieldTrial(
-          "SpdyCwnd", kSpdyCwndDivisor, "cwndDynamic", 2013, 6, 30, NULL));
-
-  trial->AppendGroup("cwnd10", kSpdyCwnd10);
-  trial->AppendGroup("cwnd16", kSpdyCwnd16);
-  trial->AppendGroup("cwndMin16", kSpdyCwndMin16);
-  trial->AppendGroup("cwndMin10", kSpdyCwndMin10);
-
-  if (parsed_command_line().HasSwitch(switches::kMaxSpdyConcurrentStreams)) {
-    int value = 0;
-    base::StringToInt(parsed_command_line().GetSwitchValueASCII(
-            switches::kMaxSpdyConcurrentStreams),
-        &value);
-    if (value > 0)
-      net::SpdySession::set_max_concurrent_streams(value);
-  }
-}
-
-// If --socket-reuse-policy is not specified, run an A/B test for choosing the
-// warmest socket.
-void ChromeBrowserMainParts::WarmConnectionFieldTrial() {
-  const CommandLine& command_line = parsed_command_line();
-  if (command_line.HasSwitch(switches::kSocketReusePolicy)) {
-    std::string socket_reuse_policy_str = command_line.GetSwitchValueASCII(
-        switches::kSocketReusePolicy);
-    int policy = -1;
-    base::StringToInt(socket_reuse_policy_str, &policy);
-
-    const int policy_list[] = { 0, 1, 2 };
-    VLOG(1) << "Setting socket_reuse_policy = " << policy;
-    SetSocketReusePolicy(policy, policy_list, arraysize(policy_list));
-    return;
-  }
-
-  const base::FieldTrial::Probability kWarmSocketDivisor = 100;
-  const base::FieldTrial::Probability kWarmSocketProbability = 33;
-
-  // Default value is USE_LAST_ACCESSED_SOCKET.
-  int last_accessed_socket = -1;
-
-  // After January 30, 2013 builds, it will always be in default group.
-  scoped_refptr<base::FieldTrial> warmest_socket_trial(
-      base::FieldTrialList::FactoryGetFieldTrial(
-          "WarmSocketImpact", kWarmSocketDivisor, "last_accessed_socket",
-          2013, 1, 30, &last_accessed_socket));
-
-  const int warmest_socket = warmest_socket_trial->AppendGroup(
-      "warmest_socket", kWarmSocketProbability);
-  const int warm_socket = warmest_socket_trial->AppendGroup(
-      "warm_socket", kWarmSocketProbability);
-
-  const int warmest_socket_trial_group = warmest_socket_trial->group();
-
-  const int policy_list[] = { warmest_socket, warm_socket,
-                              last_accessed_socket };
-  SetSocketReusePolicy(warmest_socket_trial_group, policy_list,
-                       arraysize(policy_list));
-}
-
-// If neither --enable-connect-backup-jobs or --disable-connect-backup-jobs is
-// specified, run an A/B test for automatically establishing backup TCP
-// connections when a certain timeout value is exceeded.
-void ChromeBrowserMainParts::ConnectBackupJobsFieldTrial() {
-  if (parsed_command_line().HasSwitch(switches::kEnableConnectBackupJobs)) {
-    net::internal::ClientSocketPoolBaseHelper::set_connect_backup_jobs_enabled(
-        true);
-  } else if (parsed_command_line().HasSwitch(
-        switches::kDisableConnectBackupJobs)) {
-    net::internal::ClientSocketPoolBaseHelper::set_connect_backup_jobs_enabled(
-        false);
-  } else {
-    const base::FieldTrial::Probability kConnectBackupJobsDivisor = 100;
-    // 1% probability.
-    const base::FieldTrial::Probability kConnectBackupJobsProbability = 1;
-    // After June 30, 2011 builds, it will always be in default group.
-    int connect_backup_jobs_enabled = -1;
-    scoped_refptr<base::FieldTrial> trial(
-        base::FieldTrialList::FactoryGetFieldTrial("ConnnectBackupJobs",
-            kConnectBackupJobsDivisor, "ConnectBackupJobsEnabled",
-            2011, 6, 30, &connect_backup_jobs_enabled));
-    trial->AppendGroup("ConnectBackupJobsDisabled",
-                       kConnectBackupJobsProbability);
-    const int trial_group = trial->group();
-    net::internal::ClientSocketPoolBaseHelper::set_connect_backup_jobs_enabled(
-        trial_group == connect_backup_jobs_enabled);
-  }
-}
-
-void ChromeBrowserMainParts::PredictorFieldTrial() {
-  const base::FieldTrial::Probability kDivisor = 1000;
-  // For each option (i.e., non-default), we have a fixed probability.
-  // 0.1% probability.
-  const base::FieldTrial::Probability kProbabilityPerGroup = 1;
-
-  // After June 30, 2011 builds, it will always be in default group
-  // (default_enabled_prefetch).
-  scoped_refptr<base::FieldTrial> trial(
-      base::FieldTrialList::FactoryGetFieldTrial(
-          "DnsImpact", kDivisor, "default_enabled_prefetch", 2011, 10, 30,
-          NULL));
-
-  // First option is to disable prefetching completely.
-  int disabled_prefetch = trial->AppendGroup("disabled_prefetch",
-                                              kProbabilityPerGroup);
-
-  // We're running two experiments at the same time.  The first set of trials
-  // modulates the delay-time until we declare a congestion event (and purge
-  // our queue).  The second modulates the number of concurrent resolutions
-  // we do at any time.  Users are in exactly one trial (or the default) during
-  // any one run, and hence only one experiment at a time.
-  // Experiment 1:
-  // Set congestion detection at 250, 500, or 750ms, rather than the 1 second
-  // default.
-  int max_250ms_prefetch = trial->AppendGroup("max_250ms_queue_prefetch",
-                                              kProbabilityPerGroup);
-  int max_500ms_prefetch = trial->AppendGroup("max_500ms_queue_prefetch",
-                                              kProbabilityPerGroup);
-  int max_750ms_prefetch = trial->AppendGroup("max_750ms_queue_prefetch",
-                                              kProbabilityPerGroup);
-  // Set congestion detection at 2 seconds instead of the 1 second default.
-  int max_2s_prefetch = trial->AppendGroup("max_2s_queue_prefetch",
-                                           kProbabilityPerGroup);
-  // Experiment 2:
-  // Set max simultaneous resoultions to 2, 4, or 6, and scale the congestion
-  // limit proportionally (so we don't impact average probability of asserting
-  // congesion very much).
-  int max_2_concurrent_prefetch = trial->AppendGroup(
-      "max_2 concurrent_prefetch", kProbabilityPerGroup);
-  int max_4_concurrent_prefetch = trial->AppendGroup(
-      "max_4 concurrent_prefetch", kProbabilityPerGroup);
-  int max_6_concurrent_prefetch = trial->AppendGroup(
-      "max_6 concurrent_prefetch", kProbabilityPerGroup);
-
-  if (trial->group() != disabled_prefetch) {
-    // Initialize the DNS prefetch system.
-    size_t max_parallel_resolves =
-        chrome_browser_net::Predictor::kMaxSpeculativeParallelResolves;
-    int max_queueing_delay_ms =
-        chrome_browser_net::Predictor::kMaxSpeculativeResolveQueueDelayMs;
-
-    if (trial->group() == max_2_concurrent_prefetch)
-      max_parallel_resolves = 2;
-    else if (trial->group() == max_4_concurrent_prefetch)
-      max_parallel_resolves = 4;
-    else if (trial->group() == max_6_concurrent_prefetch)
-      max_parallel_resolves = 6;
-    chrome_browser_net::Predictor::set_max_parallel_resolves(
-        max_parallel_resolves);
-
-    if (trial->group() == max_250ms_prefetch) {
-      max_queueing_delay_ms =
-         (250 * chrome_browser_net::Predictor::kTypicalSpeculativeGroupSize) /
-         max_parallel_resolves;
-    } else if (trial->group() == max_500ms_prefetch) {
-      max_queueing_delay_ms =
-          (500 * chrome_browser_net::Predictor::kTypicalSpeculativeGroupSize) /
-          max_parallel_resolves;
-    } else if (trial->group() == max_750ms_prefetch) {
-      max_queueing_delay_ms =
-          (750 * chrome_browser_net::Predictor::kTypicalSpeculativeGroupSize) /
-          max_parallel_resolves;
-    } else if (trial->group() == max_2s_prefetch) {
-      max_queueing_delay_ms =
-          (2000 * chrome_browser_net::Predictor::kTypicalSpeculativeGroupSize) /
-          max_parallel_resolves;
-    }
-    chrome_browser_net::Predictor::set_max_queueing_delay(
-        max_queueing_delay_ms);
-  }
-}
-
-void ChromeBrowserMainParts::DefaultAppsFieldTrial() {
-  std::string brand;
-  google_util::GetBrand(&brand);
-
-  // Create a 100% field trial based on the brand code.
-  if (LowerCaseEqualsASCII(brand, "ecdb")) {
-    base::FieldTrialList::CreateFieldTrial(kDefaultAppsTrialName,
-                                           kDefaultAppsTrialNoAppsGroup);
-  } else if (LowerCaseEqualsASCII(brand, "ecda")) {
-    base::FieldTrialList::CreateFieldTrial(kDefaultAppsTrialName,
-                                           kDefaultAppsTrialWithAppsGroup);
-  }
-}
-
-void ChromeBrowserMainParts::AutoLaunchChromeFieldTrial() {
-  std::string brand;
-  google_util::GetBrand(&brand);
-
-  // Create a 100% field trial based on the brand code.
-  if (auto_launch_trial::IsInExperimentGroup(brand)) {
-    base::FieldTrialList::CreateFieldTrial(kAutoLaunchTrialName,
-                                           kAutoLaunchTrialAutoLaunchGroup);
-  } else if (auto_launch_trial::IsInControlGroup(brand)) {
-    base::FieldTrialList::CreateFieldTrial(kAutoLaunchTrialName,
-                                           kAutoLaunchTrialControlGroup);
-  }
-}
-
-void ChromeBrowserMainParts::SetupUniformityFieldTrials() {
-  // One field trial will be created for each entry in this array. The i'th
-  // field trial will have |trial_sizes[i]| groups in it, including the default
-  // group. Each group will have a probability of 1/|trial_sizes[i]|.
-  const int num_trial_groups[] = { 100, 20, 10, 5, 2 };
-
-  // Declare our variation ID bases along side this array so we can loop over it
-  // and assign the IDs appropriately. So for example, the 1 percent experiments
-  // should have a size of 100 (100/100 = 1).
-  const chrome_variations::VariationID trial_base_ids[] = {
-      chrome_variations::kUniformity1PercentBase,
-      chrome_variations::kUniformity5PercentBase,
-      chrome_variations::kUniformity10PercentBase,
-      chrome_variations::kUniformity20PercentBase,
-      chrome_variations::kUniformity50PercentBase
-  };
-
-  const std::string kOneTimeRandomizedTrialName =
-      "UMA-Uniformity-Trial-%d-Percent";
-  for (size_t i = 0; i < arraysize(num_trial_groups); ++i) {
-    SetupSingleUniformityFieldTrial(true, kOneTimeRandomizedTrialName,
-                                       trial_base_ids[i], num_trial_groups[i]);
-  }
-
-  // Setup a 5% session-randomized uniformity trial.
-  const std::string kSessionRandomizedTrialName =
-      "UMA-Session-Randomized-Uniformity-Trial-%d-Percent";
-  SetupSingleUniformityFieldTrial(false, kSessionRandomizedTrialName,
-      chrome_variations::kUniformitySessionRandomized5PercentBase, 20);
-}
-
-void ChromeBrowserMainParts::DisableNewTabFieldTrialIfNecesssary() {
-  // The new tab button field trial will get created in variations_service.cc
-  // through the variations server. However, since there are no HiDPI assets
-  // for it, disable it for non-desktop layouts.
-  base::FieldTrial* trial = base::FieldTrialList::Find("NewTabButton");
-  if (trial) {
-    bool using_hidpi_assets = false;
-#if defined(ENABLE_HIDPI) && defined(OS_WIN)
-    // Mirrors logic in resource_bundle_win.cc.
-    using_hidpi_assets = ui::GetDPIScale() > 1.5;
-#endif
-    if (ui::GetDisplayLayout() != ui::LAYOUT_DESKTOP || using_hidpi_assets)
-      trial->Disable();
-  }
-}
-
-void ChromeBrowserMainParts::ChannelIDFieldTrial() {
-  chrome::VersionInfo::Channel channel = chrome::VersionInfo::GetChannel();
-  if (channel == chrome::VersionInfo::CHANNEL_CANARY) {
-    net::SSLConfigService::EnableChannelIDTrial();
-  } else if (channel == chrome::VersionInfo::CHANNEL_DEV &&
-             base::FieldTrialList::IsOneTimeRandomizationEnabled()) {
-    const base::FieldTrial::Probability kDivisor = 100;
-    // 10% probability of being in the enabled group.
-    const base::FieldTrial::Probability kEnableProbability = 10;
-    scoped_refptr<base::FieldTrial> trial =
-        base::FieldTrialList::FactoryGetFieldTrial(
-            "ChannelID", kDivisor, "disable", 2012, 8, 23, NULL);
-    trial->UseOneTimeRandomization();
-    int enable_group = trial->AppendGroup("enable", kEnableProbability);
-    if (trial->group() == enable_group)
-      net::SSLConfigService::EnableChannelIDTrial();
-  }
-}
-
 // ChromeBrowserMainParts: |SetupMetricsAndFieldTrials()| related --------------
 
-void ChromeBrowserMainParts::SetupFieldTrials(bool proxy_policy_is_set) {
-  // Note: make sure to call ConnectionFieldTrial() before
-  // ProxyConnectionsFieldTrial().
-  ConnectionFieldTrial();
-  SocketTimeoutFieldTrial();
-  // If a policy is defining the number of active connections this field test
-  // shoud not be performed.
-  if (!proxy_policy_is_set)
-    ProxyConnectionsFieldTrial();
-  prerender::ConfigurePrefetchAndPrerender(parsed_command_line());
-  SpdyFieldTrial();
-  ConnectBackupJobsFieldTrial();
-  WarmConnectionFieldTrial();
-  PredictorFieldTrial();
-  DefaultAppsFieldTrial();
-  AutoLaunchChromeFieldTrial();
-  gpu_util::InitializeForceCompositingModeFieldTrial();
-  SetupUniformityFieldTrials();
-  AutocompleteFieldTrial::Activate();
-  DisableNewTabFieldTrialIfNecesssary();
-  ChannelIDFieldTrial();
-}
-
 void ChromeBrowserMainParts::StartMetricsRecording() {
   MetricsService* metrics = g_browser_process->metrics_service();
   if (parsed_command_line_.HasSwitch(switches::kMetricsRecordingOnly) ||