Summary: public
Native iOS has a good error message, but it's in native which makes
things a little harder to track down (can't use Chrome debugger as easily).
Android has no special handling, so a cryptic "Trying to add unknown view tag..."
redbox would come up.
This puts the error handling in JS so it's shared on all platforms and can be
debugged more easily in Chrome.
Reviewed By: vjeux
Differential Revision: D2606064
fb-gh-sync-id: 5295a44a028c7be79d60dbaf0b5d59fd0a56fdde