Pulling user experiment code from BrowserDistribution to a new class.

chrome/installer/setup/setup_main.cc

Index: chrome/installer/setup/setup_main.cc
diff --git a/chrome/installer/setup/setup_main.cc b/chrome/installer/setup/setup_main.cc
index 12fd98d907ef58013a7723727b809ffd55c2436a..8c07a84c4c41298de7dee773de04e28bc82affc5 100644
--- a/chrome/installer/setup/setup_main.cc
+++ b/chrome/installer/setup/setup_main.cc
@@ -60,6 +60,7 @@
 #include "chrome/installer/util/master_preferences_constants.h"
 #include "chrome/installer/util/self_cleaning_temp_dir.h"
 #include "chrome/installer/util/shell_util.h"
+#include "chrome/installer/util/user_experiment.h"
 #include "chrome/installer/util/util_constants.h"
 
 #include "installer_util_strings.h"  // NOLINT
@@ -923,7 +924,7 @@ installer::InstallStatus InstallProductsHelper(
       for (Products::const_iterator it = products.begin(); it < products.end();
            ++it) {
         const Product& product = **it;
-        product.distribution()->LaunchUserExperiment(setup_path,
+        installer::user_experiment::LaunchUserExperimentIfRequired(setup_path,
             install_status, *installer_version, product, system_install);
       }
     }
@@ -1429,8 +1430,8 @@ bool HandleNonInstallCmdLineOptions(const InstallationState& original_state,
            ++it) {
         const Product& product = **it;
         BrowserDistribution* browser_dist = product.distribution();
-        browser_dist->InactiveUserToastExperiment(
-            flavor, ASCIIToUTF16(experiment_group), product,
+        installer::user_experiment::InactiveUserToastExperimentIfRequired(
+            browser_dist, flavor, ASCIIToUTF16(experiment_group), product,
             installer_state->target_path());
       }
     }
@@ -1449,9 +1450,9 @@ bool HandleNonInstallCmdLineOptions(const InstallationState& original_state,
                    << browser_dist->GetAppShortCutName()
                    << " found for system-level toast.";
       } else {
-        browser_dist->LaunchUserExperiment(cmd_line.GetProgram(),
-                                           installer::REENTRY_SYS_UPDATE,
-                                           installed_version, product, true);
+        installer::user_experiment::LaunchUserExperimentIfRequired(
+            cmd_line.GetProgram(), installer::REENTRY_SYS_UPDATE,
+            installed_version, product, true);
       }
     }
   } else if (cmd_line.HasSwitch(