This is a testharness.js-based test.
[FAIL] CSSMediaRule interface: attribute matches
  assert_true: The prototype object must have a property "matches" expected true got false
[FAIL] CSSMediaRule interface: cssMediaRule must inherit property "matches" with the proper type
  assert_inherits: property "matches" not found in prototype chain
[FAIL] CSSSupportsRule interface: attribute matches
  assert_true: The prototype object must have a property "matches" expected true got false
[FAIL] CSSSupportsRule interface: cssSupportsRule must inherit property "matches" with the proper type
  assert_inherits: property "matches" not found in prototype chain
Harness: the test ran to completion.