Re: [html-tests] Update some element interfaces to match the spec (#2883)

@domenic can you review the custom element aspect (Search for `foo-` in the diff)? @ayg has LGTMed the rest.

View on GitHub: https://github.com/w3c/web-platform-tests/pull/2883#issuecomment-216243753

Received on Monday, 2 May 2016 14:01:50 UTC