1 files changed, 44 insertions, 0 deletions
diff --git a/chrome/browser/chrome_browser_field_trials_mobile.cc b/chrome/browser/chrome_browser_field_trials_mobile.cc
index 7fb1896..5e17ca7 100644
--- a/chrome/browser/chrome_browser_field_trials_mobile.cc
+++ b/chrome/browser/chrome_browser_field_trials_mobile.cc
@@ -9,6 +9,7 @@
 #include "base/command_line.h"
 #include "base/metrics/field_trial.h"
 #include "base/prefs/pref_service.h"
+#include "chrome/common/chrome_switches.h"
 #include "chrome/common/chrome_version_info.h"
 
 namespace chrome {
@@ -51,12 +52,55 @@ void DataCompressionProxyFieldTrial() {
           << ". Selected group id: " << v;
 }
 
+void NewTabButtonInToolbarFieldTrial(const CommandLine& parsed_command_line) {
+  // Do not enable this field trials for tablet devices.
+  if (parsed_command_line.HasSwitch(switches::kTabletUI))
+    return;
+
+  const char kPhoneNewTabToolbarButtonFieldTrialName[] =
+      "PhoneNewTabToolbarButton";
+  const base::FieldTrial::Probability kPhoneNewTabToolbarButtonDivisor = 100;
+
+  // 50/100 = 50% for Non-Stable users.
+  //  0/100 = 0%  for Stable users.
+  const base::FieldTrial::Probability kPhoneNewTabToolbarButtonNonStable = 50;
+  const base::FieldTrial::Probability kPhoneNewTabToolbarButtonStable = 0;
+  const char kEnabled[] = "Enabled";
+  const char kDisabled[] = "Disabled";
+
+  // Find out if this is a stable channel.
+  const bool kIsStableChannel =
+      chrome::VersionInfo::GetChannel() == chrome::VersionInfo::CHANNEL_STABLE;
+
+  // Experiment enabled until Jan 1, 2015. By default, disabled.
+  scoped_refptr<base::FieldTrial> trial(
+      base::FieldTrialList::FactoryGetFieldTrial(
+          kPhoneNewTabToolbarButtonFieldTrialName,
+          kPhoneNewTabToolbarButtonDivisor,
+          kDisabled, 2015, 1, 1, NULL));
+
+  // We want our trial results to be persistent.
+  trial->UseOneTimeRandomization();
+  const int kEnabledGroup = trial->AppendGroup(
+      kEnabled,
+      kIsStableChannel ?
+          kPhoneNewTabToolbarButtonStable : kPhoneNewTabToolbarButtonNonStable);
+
+  const int v = trial->group();
+  VLOG(1) << "Phone NewTab toolbar button enabled group id: " << kEnabledGroup
+          << ". Selected group id: " << v;
+}
+
 }  // namespace
 
 void SetupMobileFieldTrials(const CommandLine& parsed_command_line,
                             const base::Time& install_time,
                             PrefService* local_state) {
   DataCompressionProxyFieldTrial();
+
+#if defined(OS_ANDROID)
+  NewTabButtonInToolbarFieldTrial(parsed_command_line);
+#endif
 }
 
 }  // namespace chrome