RxJS version:
5.5.6

Code to reproduce:

const subscription = fromEvent<KeyboardEvent>(document.body, 'keydown', true).subscribe(() => {});

// To check the bound keyboard listeners, use `getEventListeners(document.body).keydown` in the Chrome dev tools.

subscription.unsubscribe();

// Run `getEventListeners(document.body).keydown` again to check the amount of event listeners.

Expected behavior:
The keydown event should be removed.

Actual behavior:
The keydown event isn't being removed.

Additional information:
The issue only seems to happen when passing in the third argument to fromEvent. It passes the argument along to addEventListener correctly, however the same set of arguments have to be passed back to removeEventListener in order for the event to be removed when unsubscribing.

Related issue: angular/components#10143
Related PR: angular/components#10160