TreatNullAs

TreatNullAs

[1] Merge pull request #1131 from foolip/patch-1 (aboba著, ) <https://github.com/w3c/webrtc-pc/commit/06288385e2c07d20e593d960662bfd4a55557b35>

[2] Fix Web IDL extended attribute usage for recent changes (domenic著, ) <https://github.com/whatwg/dom/commit/f9ede86ea35753b40f6070352e2f150bc1bd2482>

[3] Allow extended attributes to apply to types (#286) (domenic著, ) <https://github.com/heycam/webidl/commit/faaaaa9ffb548a303db362a09e4b1504c4605e0c>

[4] Fix Web IDL extended attribute usage for recent changes (domenic著, ) <https://github.com/whatwg/html/commit/793ace83447c9420a4dbc14f9bb14d3c35550f0a>