Index: ios/chrome/browser/metrics/tab_usage_recorder.mm |
diff --git a/ios/chrome/browser/metrics/tab_usage_recorder.mm b/ios/chrome/browser/metrics/tab_usage_recorder.mm |
index 14405ace6728337252047bc10c8f86326abb04e7..b8cd3ba755c83c10c1579699f08b611a79172efe 100644 |
--- a/ios/chrome/browser/metrics/tab_usage_recorder.mm |
+++ b/ios/chrome/browser/metrics/tab_usage_recorder.mm |
@@ -10,6 +10,10 @@ |
#import "ios/chrome/browser/tabs/tab.h" |
#import "ios/web/web_state/ui/crw_web_controller.h" |
+#if !defined(__has_feature) || !__has_feature(objc_arc) |
+#error "This file requires ARC support." |
+#endif |
+ |
const char kTabUsageHistogramPrefix[] = "Tab"; |
// The histogram recording the state of the tab the user switches to. |