Re: [html-tests] Make all parameters to initMessageEvent() optional except the first one (#5044)

These tests are now available on [w3c-test.org](https://w3c-test.org/submissions/5044)

View on GitHub: https://github.com/w3c/web-platform-tests/pull/5044#issuecomment-284194417

Received on Sunday, 5 March 2017 00:04:19 UTC