[ObjC ARC] Converts ios/chrome/browser/crash_report to ARC

ios/chrome/browser/crash_report/crash_report_multi_parameter.mm

Index: ios/chrome/browser/crash_report/crash_report_multi_parameter.mm
diff --git a/ios/chrome/browser/crash_report/crash_report_multi_parameter.mm b/ios/chrome/browser/crash_report/crash_report_multi_parameter.mm
index 15a7625d6d47866019c2396df3c1523ced7def90..61df0793cfea7497b0929fa1c6416c2c7dd09a65 100644
--- a/ios/chrome/browser/crash_report/crash_report_multi_parameter.mm
+++ b/ios/chrome/browser/crash_report/crash_report_multi_parameter.mm
@@ -13,6 +13,10 @@
 #include "base/values.h"
 #import "ios/chrome/browser/crash_report/breakpad_helper.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 // Maximum size of a breakpad parameter. The length of the dictionary serialized
 // into JSON cannot exceed this length. See declaration in (BreakPad.h) for