getRegistration in ServiceWorkerContainer's optional parameter is missing from 2.6.1

[cheung-chifung]

In 2.5.2, getRegistration has an optional parameter clientURL?: USVString, which is missing from 2.6.1.

According to MDN, this parameter is optional.

https://developer.mozilla.org/en-US/docs/Web/API/ServiceWorkerContainer/getRegistration

Maybe a coding miss in this diff: https://github.com/Microsoft/TypeScript/pull/18774/files#diff-46fd87925e4552c166ec188712741c3fL9534

TypeScript Version: 2.6.1

Code

Expected behavior:

clientURL should be acceptable.

Actual behavior:

[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.

[cheung-chifung]

I fixed it in Microsoft/TSJS-lib-generator.
Please check: microsoft/TypeScript-DOM-lib-generator#323