Bug 219278

Since r266584, we've suffered from an annoying unsupported browser warning when using Google Docs. We don't have many options to avoid it. I'm afraid that Firefox or Chrome quirks are too risky, since these seem to tempt Google into using web platform features that WebKit does not support. The safest quirk is the macOS platform quirk, but that doesn't work well here because it breaks various keyboard shortcuts like Ctrl+A and Ctrl+Z. So Internet Explorer quirk is really the last card we have left.

I think this is the safest Google quirk we've ever had, in that it's pretty unlikely that Google will try to send Internet Explorer anything that doesn't work in WebKit. However, it will break eventually, whenever Google decides that Internet Explorer is no longer supported. I guess that date is probably at least five years away, so we can only hope that Google drops this anticompetitive nonsense before then.