[WM] Update iframe fix for f8d706eeddd3efa822e8506575421f169e1806c4
Variable rewriting fixes

- We didn't rewrite object literals at all instead of just not object keys
- We unnecessarily rewrote function declaration argument names
Set location.origin to "null"

Compatibility with Firetext
Firetext requires that location.origin === message.origin
Don't feed DOM APIs Airborn URLs