Summary:
This was originally introduced so we could squash multiple instances of the same error at the client side and only report one instance of them.
Now we've moved to doing the aggregation server side, which is more powerful, so this is no longer necessary. We've also seen a case of these Error objects appearing opaque making it hard to see the underlying problem, so removing it entirely.
Reviewed By: passy
Differential Revision: D14576715
fbshipit-source-id: b285dcb5249e209f9008a14ac6a2f226f3aa82d7
bf9be74ad2