Mark imported/w3c/web-platform-tests/payment-request/payment-request-show-method.https.html as flaky on iOS.
https://bugs.webkit.org/show_bug.cgi?id=177391

Unreviewed test gardening.

* platform/ios/TestExpectations:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@222410 268f45cc-cd09-0410-ab3c-d52691b4dbfc
diff --git a/LayoutTests/platform/ios/TestExpectations b/LayoutTests/platform/ios/TestExpectations
index 1329dc7..2561775 100644
--- a/LayoutTests/platform/ios/TestExpectations
+++ b/LayoutTests/platform/ios/TestExpectations
@@ -3179,3 +3179,5 @@
 http/tests/multipart/load-last-non-html-frame.php [ Failure  ]
 
 webkit.org/b/177366 http/tests/security/frameNavigation/sandbox-ALLOWED-top-navigation-with-user-gesture-1.html [ Pass Timeout ]
+
+webkit.org/b/177391 imported/w3c/web-platform-tests/payment-request/payment-request-show-method.https.html [ Pass Failure ]