API discovery excludes anything not in Object.getOwnPropertyNames()

Umbrella bug for the following issue (example drawn from Safari 9 data):

```js
Object.getOwnPropertyNames(window).filter(function(name) { return name === 'indexedDB'; }).length
// 0
window.hasOwnProperty('indexedDB')
// true
```

More generally: current API discovery strategy misses any API that appears when accessed directly, but appears nowhere in `Object.getOwnPropertyNames()` along the object's prototype chain.