Isolated iframe focus

This test:
  1. Focuses an input element in the parent window.
  2. Focuses an input element within an iframe.
  3. Waits a short bit.
  4. Calls element.blur() on the element in the parent window.
Observed:
  1. Focused element inside the iframe loses focus.
Expected:
  1. Blur on element which is not the actively focused element has no effect on the current focus.
Dummy input element, should not be focused.

This input element in the iframe should remain focused.