The following layout test is flaky on Windows:
Looks like it is more than windows.
According to the flakiness dashboard it is flaky on all of macOS as well:
@@ -15,7 +15,7 @@
Caught attempt to access non-existant object store on the transaction
Caught attempt to access valid object store on a transaction that is already finishing
put failed (because transaction was aborted)
-First version change transaction unexpected error - [object Event]
+First version change transaction abort
PASS successfullyParsed is true
Marked as flaky https://trac.webkit.org/changeset/225576/webkit
Test is also a flaky failure on iOS Simulator WK2 and Debug.
While testing for a recent regression on the dashboard, found that this test is also flaky on those platforms. Updating test expectations for iOS.