This is a testharness.js-based test.
[FAIL] attachShadow() on an adopted built-in host: shadow root uses the node document realm
  assert_true: shadow root is from the node document's (top-level) realm expected true got false
[FAIL] attachShadow() on an adopted custom element host: shadow root uses the node document realm
  assert_true: shadow root is from the node document's (top-level) realm expected true got false
Harness: the test ran to completion.