Add Chromium versions for api.CustomEvent.initCustomEvent (#11889)
Add Chromium versions for api.CustomEvent.initCustomEvent (#11889)

This PR adds real values for Chromium (Chrome, Opera, Samsung Internet, WebView Android) for the `initCustomEvent` member of the `CustomEvent` API, based upon results from the [mdn-bcd-collector](https://mdn-bcd-collector.appspot.com) project (v3.2.2).

Tests Used: https://mdn-bcd-collector.appspot.com/tests/api/CustomEvent/initCustomEvent

Remove notes that came from https://github.com/mdn/browser-compat-data/pull/1677.
mdn/browser-compat-data,mdn/browser-compat-data,chrisdavidmills/browser-compat-data,chrisdavidmills/browser-compat-data