CONSOLE WARNING: line 9: dummy log entry to avoid an empty -expected.txt in virtual/
This is a testharness.js-based test.
PASS Setup 
FAIL Set HTMLMediaElement session when networkState is NETWORK_EMPTY Failed to construct 'MediaSession': Missing platform implementation.
FAIL Set HTMLMediaElement session when networkState is NETWORK_NO_SOURCE Failed to construct 'MediaSession': Missing platform implementation.
FAIL Set HTMLMediaElement session during or after load assert_throws: function "function () { mediaElement.session = new MediaSession(); }" threw object "NotSupportedError: Failed to construct 'MediaSession': Mi..." that is not a DOMException InvalidStateError: property "code" is equal to 9, expected 11
Harness: the test ran to completion.