Revert of Reduce plugin_metrics_provider_ usage in MetricsService

chrome/browser/metrics/metrics_service.cc

Index: chrome/browser/metrics/metrics_service.cc
diff --git a/chrome/browser/metrics/metrics_service.cc b/chrome/browser/metrics/metrics_service.cc
index e380d71190e1bcbb751419263bec066da4a4380b..c616651b2882537b5cc1fe5805301fc7f0569fde 100644
--- a/chrome/browser/metrics/metrics_service.cc
+++ b/chrome/browser/metrics/metrics_service.cc
@@ -1313,6 +1313,7 @@
 
 void MetricsService::LogPluginLoadingError(const base::FilePath& plugin_path) {
 #if defined(ENABLE_PLUGINS)
+  // TODO(asvitkine): Move this out of here.
   plugin_metrics_provider_->LogPluginLoadingError(plugin_path);
 #endif
 }
@@ -1333,6 +1334,7 @@
 void MetricsService::RecordCurrentState(PrefService* pref) {
   pref->SetInt64(prefs::kStabilityLastTimestampSec, Time::Now().ToTimeT());
 
-  for (size_t i = 0; i < metrics_providers_.size(); ++i)
-    metrics_providers_[i]->RecordCurrentState();
-}
+#if defined(ENABLE_PLUGINS)
+  plugin_metrics_provider_->RecordPluginChanges();
+#endif
+}