[whatwg] A suggestion, if postMessage becomes async

[Jeff Walden]

Anne van Kesteren wrote:
> How is omitting the argument any less explicit than providing a "*" as 
> argument? I would prefer we keep that part of the API as is.

It's far easier to forget to provide the origin than it is to accidentally provide "*".  If you omit an origin with this API, one way or another you're going to get an exception (either a syntax error or a not-enough-arguments error, depending on how DOM bindings work in the browser).

Jeff