TreatUndefinedAs

TreatUndefinedAs

[1] Merge branch 'gh-pages' of https://github.com/Ms2ger/webidl into Ms2ger-... · 40f1793 · heycam/webidl ( ( 版)) <https://github.com/heycam/webidl/commit/40f17934c491cb988ef9447a6cee5458cdf2b164>