When I am converting setTimeout() to use V8Function (see  bug 866610 ), https://github.com/web-platform-tests/wpt/blob/master/html/browsers/browsing-the-web/unloading-documents/unload/007.html consistently times out.

The linked test does a series of navigation in an iframe. It goes roughly like this:

1. 007.html creates a frame with 007-1.html
2. 007-1.html then navigates to 007-2.html
3. 007-2.html calls the `start_test()` function defined in 007.html, which sets a timer to call `t.done()`, thus finishing the test
4. 007-2.html navigates away from itself using `history.back()`

The issue here is that the timeout scheduled by `start_test()` is not getting called, and that is because the incumbent settings object is incorrectly set to be 007-2.html's, which by that point is already detached, rather than 007.html's.

However, this doesn't seem to be what the HTML Standard says. For this case, it seems like by definition ("the most-recently-entered author function or script on the stack, or the author function or script that originally scheduled the currently-running callback.") the incumbent realm when `setTimeout()` is called should be 007.html's, as `start_test()` is defined in 007.html.