Function js::jsapi::WatchGuts

pub unsafe extern "C" fn WatchGuts(
    cx: *mut JSContext, 
    obj: HandleObject, 
    id: HandleId, 
    callable: HandleObject
) -> bool

Add a watchpoint -- in the Object.prototype.watch sense -- to |obj| for the property |id|, using the callable object |callable| as the function to be called for notifications.

This is an internal function exposed -- temporarily -- only so that DOM proxies can be watchable. Don't use it! We'll soon kill off the Object.prototype.{,un}watch functions, at which point this will go too.