Clean up UMA 3g experiment and unify metrics enabled pref for Android

components/metrics/metrics_service_accessor.cc

Index: components/metrics/metrics_service_accessor.cc
diff --git a/components/metrics/metrics_service_accessor.cc b/components/metrics/metrics_service_accessor.cc
index de99a258680357eb0be174b0c5e6508c7969008d..786895b40a1584ade9a51b80a8f5a300a777991b 100644
--- a/components/metrics/metrics_service_accessor.cc
+++ b/components/metrics/metrics_service_accessor.cc
@@ -16,20 +16,13 @@ namespace metrics {
 // static
 bool MetricsServiceAccessor::IsMetricsReportingEnabled(
     PrefService* pref_service) {
-  return IsMetricsReportingEnabledWithPrefValue(
-      pref_service->GetBoolean(prefs::kMetricsReportingEnabled));
-}
-
-// static
-bool MetricsServiceAccessor::IsMetricsReportingEnabledWithPrefValue(
-    bool enabled_in_prefs) {
 #if defined(GOOGLE_CHROME_BUILD)
   // In official builds, disable metrics when reporting field trials are
   // forced; otherwise, use the value of the user's preference to determine
   // whether to enable metrics reporting.
   return !base::CommandLine::ForCurrentProcess()->HasSwitch(
              switches::kForceFieldTrials) &&
-         enabled_in_prefs;
+         pref_service->GetBoolean(prefs::kMetricsReportingEnabled);
 #else
   // In non-official builds, disable metrics reporting completely.
   return false;