Apply Referrer-Policy header when following redirects

ios/web/public/referrer_util_unittest.cc

Index: ios/web/public/referrer_util_unittest.cc
diff --git a/ios/web/public/referrer_util_unittest.cc b/ios/web/public/referrer_util_unittest.cc
index 0f5f75f8747c0e951ff282539ae07fe81f28ed6f..6d1e9c10a90d44976e2e48f5e8fac83e4042c17a 100644
--- a/ios/web/public/referrer_util_unittest.cc
+++ b/ios/web/public/referrer_util_unittest.cc
@@ -164,6 +164,9 @@ TEST(ReferrerUtilTest, PolicyForNavigation) {
         EXPECT_TRUE(policy == ReferrerPolicyDefault ||
                     policy == ReferrerPolicyNoReferrerWhenDowngrade);
         break;
+      case net::URLRequest::MAX_REFERRER_POLICY:
+        FAIL();
+        break;
     }
   }
 }