Since navigator.plugins and navigator.mimeTypes always return empty arrays, we no longer need to expose the Plugin or MimeType types.

Safari iOS no longer exposes the Plugin and MimeType types, though it does expose PluginArray and MimeTypeArray (because they are the return types of navigator.plugins and navigator.mimeTypes):

https://github.com/whatwg/html/issues/6003#issuecomment-762424809

Chromium removed the Plugin and MimeTypes in https://bugs.chromium.org/p/chromium/issues/detail?id=1168645.

Related WHATWG discussion about removing plugin code:

https://github.com/whatwg/html/issues/6003

Note that window.Plugin and window.MimeType are visible from the web. It may have a compatibility impact.

Chromium removed the Plugin and MimeTypes in https://bugs.chromium.org/p/chromium/issues/detail?id=1168645.

They didn't (yet). The issue is still open and I confirmed that Chrome Canary still has window.Plugin and window.MimeType.

FYI, bug 1682030 will stub these C++ classes so they are still types as far as JS is concerned but they do nothing.

Oops. My last comment was in reference to MimeTypeArray and PluginArray, not MimeType and Plugin. MimeType and Plugin are removed in bug 1682030.

Reopening this because I want to investigate some of the Chromium discussion.

I think it should be safe to remove them, but maybe we should do it behind a flag initially so we can revert in case a site does something with them.

Sounds good. I'll take care of that in bug 1682030.

We went a different direction on the spec, per https://bugzilla.mozilla.org/show_bug.cgi?id=1720353 . It might be best to close this.

Closing as invalid since the plan has changed to bug 1720353.