[ObjC ARC] Converts ios/chrome/browser/metrics:metrics to ARC.Automatically generated ARCMigrate …

ios/chrome/browser/metrics/ios_chrome_metrics_services_manager_client.mm

Index: ios/chrome/browser/metrics/ios_chrome_metrics_services_manager_client.mm
diff --git a/ios/chrome/browser/metrics/ios_chrome_metrics_services_manager_client.mm b/ios/chrome/browser/metrics/ios_chrome_metrics_services_manager_client.mm
index 869a4c9dcc2365b9d848f2b0a1c5b48f522f1f3c..e5693393ed5e36fce44c8e2430980cce497bfcd6 100644
--- a/ios/chrome/browser/metrics/ios_chrome_metrics_services_manager_client.mm
+++ b/ios/chrome/browser/metrics/ios_chrome_metrics_services_manager_client.mm
@@ -21,6 +21,10 @@
 #include "ios/chrome/browser/variations/ios_ui_string_overrider_factory.h"
 #include "ios/public/provider/chrome/browser/chrome_browser_provider.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 
 void PostStoreMetricsClientInfo(const metrics::ClientInfo& client_info) {}