This is a testharness.js-based test.
[FAIL] Navigations to about:srcdoc via window.location must be blocked
  promise_test: Unhandled rejection with value: object "Error: Received message "srcdoc ready" but expected to receive no message"
[FAIL] Navigations to about:srcdoc?query via window.location within an about:srcdoc document must be blocked
  promise_test: Unhandled rejection with value: object "Error: Received message "srcdoc ready" but expected to receive no message"
[FAIL] Navigations to about:srcdoc via window.open() must be blocked
  promise_test: Unhandled rejection with value: object "Error: Received message "srcdoc ready" but expected to receive no message"
Harness: the test ran to completion.