[ObjC ARC] Reland of Converts ios/chrome/browser/ui:ui to ARC.

ios/chrome/browser/ui/file_locations.mm

Index: ios/chrome/browser/ui/file_locations.mm
diff --git a/ios/chrome/browser/ui/file_locations.mm b/ios/chrome/browser/ui/file_locations.mm
index f3c55e955beab6849438ef9bd51379fd50ef2a50..21e87e37755a74dbc5c332fe955c16df77715338 100644
--- a/ios/chrome/browser/ui/file_locations.mm
+++ b/ios/chrome/browser/ui/file_locations.mm
@@ -9,6 +9,10 @@
 #include "base/strings/sys_string_conversions.h"
 #include "ios/chrome/browser/application_context.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 // English is the default locale for the Terms of Service.
 const char kEnglishLocale[] = "en";