Add StyleSheetList and CSSRuleList to dom.iterable.d.ts

[cnshenj]

TypeScript Version: 2.8.1

Search Terms: StyleSheetList iterable

Code

// A *self-contained* demonstration of the problem follows...
// Test this by running `tsc` on the command-line, rather than through another build tool such as Gulp, Webpack, etc.
for (const styleSheet of document.styleSheets) {
}

Both latest Chrome 65 and Firefox 59 support iterable on StyleSheetList and CSSRuleList.
I can submitted a PR if needed.

Expected behavior:
Code compiled without error.

Actual behavior:
Type 'StyleSheetList' is not an array type or a string type or does not have a 'Symbol.iterator' method that returns an iterator.

Playground Link:

Related Issues:

[mhegazy]

PRs welcomed. You can find more information about contributing lib.d.ts fixes at https://github.com/Microsoft/TypeScript/blob/master/CONTRIBUTING.md#contributing-libdts-fixes.

[Joozty]

I guess this issue can be closed. It's already part of it here and here.