This is a testharness.js-based test.
[FAIL] In-viewport loading=lazy iframe does not block the load event
  assert_true: The visible iframe should not block the load event expected true got false
[FAIL] In-viewport loading=lazy visibility:hidden iframe does not block the load event
  assert_true: The hidden iframe should not block the load event expected true got false
Harness: the test ran to completion.