Index: chrome/browser/chrome_browser_field_trials_desktop.cc |
diff --git a/chrome/browser/chrome_browser_field_trials_desktop.cc b/chrome/browser/chrome_browser_field_trials_desktop.cc |
index 4d6ff32eb5af9964684075e8915a41097cae8485..6f2b6fb803d63bbebf32b4aecf4ae53388ddedf8 100644 |
--- a/chrome/browser/chrome_browser_field_trials_desktop.cc |
+++ b/chrome/browser/chrome_browser_field_trials_desktop.cc |
@@ -9,6 +9,7 @@ |
#include "apps/field_trial_names.h" |
#include "apps/pref_names.h" |
#include "base/command_line.h" |
+#include "base/environment.h" |
#include "base/metrics/field_trial.h" |
#include "base/prefs/pref_service.h" |
#include "base/strings/string_util.h" |
@@ -20,6 +21,7 @@ |
#include "chrome/browser/profiles/profiles_state.h" |
#include "chrome/browser/safe_browsing/safe_browsing_blocking_page.h" |
#include "chrome/browser/ui/sync/one_click_signin_helper.h" |
+#include "chrome/common/chrome_constants.h" |
#include "chrome/common/chrome_switches.h" |
#include "chrome/common/chrome_version_info.h" |
#include "chrome/common/metrics/variations/variations_util.h" |
@@ -91,6 +93,50 @@ void SetupLowLatencyFlashAudioFieldTrial() { |
trial->AppendGroup(content::kLowLatencyFlashAudioFieldTrialEnabledName, 25); |
} |
+void SetupPreReadFieldTrial() { |
+ // The chrome executable will have set (or not) an environment variable with |
+ // the group name into which this client belongs. |
+ std::string group; |
+ scoped_ptr<base::Environment> env(base::Environment::Create()); |
+ if (!env->GetVar(chrome::kPreReadEnvironmentVariable, &group) || |
+ group.empty()) { |
+ return; |
+ } |
+ |
+ // Initialize the field trial. We declare all of the groups here (so that |
+ // the dashboard creation tools can find them) but force the probability |
+ // of being assigned to the group already chosen by the executable, if any, |
+ // to 100%. |
+ scoped_refptr<base::FieldTrial> trial( |
+ base::FieldTrialList::FactoryGetFieldTrial( |
+ "BrowserPreReadExperiment", 100, "100-pct-default", |
+ 2014, 7, 1, base::FieldTrial::SESSION_RANDOMIZED, NULL)); |
+ trial->AppendGroup("100-pct-control", group == "100-pct-control" ? 100 : 0); |
+ trial->AppendGroup("95-pct", group == "95-pct" ? 100 : 0); |
+ trial->AppendGroup("90-pct", group == "90-pct" ? 100 : 0); |
+ trial->AppendGroup("85-pct", group == "85-pct" ? 100 : 0); |
+ trial->AppendGroup("80-pct", group == "80-pct" ? 100 : 0); |
+ trial->AppendGroup("75-pct", group == "75-pct" ? 100 : 0); |
+ trial->AppendGroup("70-pct", group == "70-pct" ? 100 : 0); |
+ trial->AppendGroup("65-pct", group == "65-pct" ? 100 : 0); |
+ trial->AppendGroup("60-pct", group == "60-pct" ? 100 : 0); |
+ trial->AppendGroup("55-pct", group == "55-pct" ? 100 : 0); |
+ trial->AppendGroup("50-pct", group == "50-pct" ? 100 : 0); |
+ trial->AppendGroup("45-pct", group == "45-pct" ? 100 : 0); |
+ trial->AppendGroup("40-pct", group == "40-pct" ? 100 : 0); |
+ trial->AppendGroup("35-pct", group == "35-pct" ? 100 : 0); |
+ trial->AppendGroup("30-pct", group == "30-pct" ? 100 : 0); |
+ trial->AppendGroup("25-pct", group == "25-pct" ? 100 : 0); |
+ trial->AppendGroup("20-pct", group == "20-pct" ? 100 : 0); |
+ trial->AppendGroup("15-pct", group == "15-pct" ? 100 : 0); |
+ trial->AppendGroup("10-pct", group == "10-pct" ? 100 : 0); |
+ trial->AppendGroup("5-pct", group == "5-pct" ? 100 : 0); |
+ trial->AppendGroup("0-pct", group == "0-pct" ? 100 : 0); |
+ |
+ // We have to call group in order to mark the experiment as active. |
+ trial->group(); |
+} |
+ |
} // namespace |
void SetupDesktopFieldTrials(const CommandLine& parsed_command_line, |
@@ -104,6 +150,7 @@ void SetupDesktopFieldTrials(const CommandLine& parsed_command_line, |
DisableShowProfileSwitcherTrialIfNecessary(); |
SetupAppLauncherFieldTrial(local_state); |
SetupLowLatencyFlashAudioFieldTrial(); |
+ SetupPreReadFieldTrial(); |
} |
} // namespace chrome |