[ObjC ARC] Converts ios/chrome/browser/open_from_clipboard:open_from_clipboard to ARC.Automatical…

ios/chrome/browser/open_from_clipboard/create_clipboard_recent_content.mm

Index: ios/chrome/browser/open_from_clipboard/create_clipboard_recent_content.mm
diff --git a/ios/chrome/browser/open_from_clipboard/create_clipboard_recent_content.mm b/ios/chrome/browser/open_from_clipboard/create_clipboard_recent_content.mm
index 6ebb7028e7378931af8038053c9e3a09c545eddb..52f6cc785fe7b96953ad4078226002e564578571 100644
--- a/ios/chrome/browser/open_from_clipboard/create_clipboard_recent_content.mm
+++ b/ios/chrome/browser/open_from_clipboard/create_clipboard_recent_content.mm
@@ -9,6 +9,10 @@
 #include "ios/chrome/browser/chrome_url_constants.h"
 #include "ios/chrome/common/app_group/app_group_constants.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 std::unique_ptr<ClipboardRecentContent> CreateClipboardRecentContentIOS() {
   return base::MakeUnique<ClipboardRecentContentIOS>(
       kChromeUIScheme, app_group::GetGroupUserDefaults());