Add a new App launcher promo to the apps page / NTP.

chrome/browser/chrome_browser_field_trials.cc

Index: chrome/browser/chrome_browser_field_trials.cc
diff --git a/chrome/browser/chrome_browser_field_trials.cc b/chrome/browser/chrome_browser_field_trials.cc
index 0a0c9a8c8fd5b9a6133edb0de004dbab1364f459..1aa4658ac6a7ae822fc79fceeeb97d6c007e93a4 100644
--- a/chrome/browser/chrome_browser_field_trials.cc
+++ b/chrome/browser/chrome_browser_field_trials.cc
@@ -6,8 +6,11 @@
 
 #include <string>
 
+#include "apps/field_trial_names.h"
+#include "apps/pref_names.h"
 #include "base/command_line.h"
 #include "base/metrics/field_trial.h"
+#include "base/prefs/pref_service.h"
 #include "base/string_util.h"
 #include "base/stringprintf.h"
 #include "base/strings/string_number_conversions.h"
@@ -26,6 +29,7 @@
 #include "chrome/common/chrome_version_info.h"
 #include "chrome/common/metrics/variations/uniformity_field_trials.h"
 #include "chrome/common/metrics/variations/variations_util.h"
+#include "chrome/common/pref_names.h"
 #include "net/socket/client_socket_pool_base.h"
 #include "net/spdy/spdy_session.h"
 #include "ui/base/layout.h"
@@ -56,13 +60,21 @@ ChromeBrowserFieldTrials::ChromeBrowserFieldTrials(
 ChromeBrowserFieldTrials::~ChromeBrowserFieldTrials() {
 }
 
-void ChromeBrowserFieldTrials::SetupFieldTrials(
-    const base::Time& install_time) {
+void ChromeBrowserFieldTrials::SetupFieldTrials(PrefService* local_state) {
+  const base::Time install_time = base::Time::FromTimeT(
+      local_state->GetInt64(prefs::kInstallDate));
+  DCHECK(!install_time.is_null());
   chrome_variations::SetupUniformityFieldTrials(install_time);
   SetUpSimpleCacheFieldTrial();
 #if !defined(OS_ANDROID)
   SetupDesktopFieldTrials();
 #endif  // defined(OS_ANDROID)
+  // This is not quite a field trial initialization, but it's an initialization
+  // that depends on a field trial, so why not? :-)
+  if (base::FieldTrialList::FindFullName(apps::kLauncherPromoTrialName) ==

[Alexei Svitkine (slow), 2013/03/22 16:57:35]

Please encapsulate this in a separate function and call it from
SetupDesktopFieldTrials().

[MAD, 2013/03/22 17:11:35]

Done.

+      apps::kResetShowLauncherPromoPrefGroup) {
+    local_state->SetBoolean(apps::prefs::kShowAppLauncherPromo, true);
+  }
 }
 
 void ChromeBrowserFieldTrials::SetupDesktopFieldTrials() {