Pass global object to static methods

[TimothyGu]

This is needed for things like DOMRect's fromRect().

[domenic]

Continuing the conversation from #211: I think I like Chromium's mechanism, where by default you don't get the global object passed, but you can opt in with an extended attribute. I'm thinking [WebIDL2JSCallWithGlobal] which makes the first argument always be the global object.

What do you think?

[TimothyGu]

That works.