Mode: force_next
Version: 53.0.2768.0
Reproduction Steps: 
1. Enable CVox and open two tabs such as www.google.com and www.yahoo.com and ensure that you have multiple windows open as well, such as Hangouts and Chrome.
2. Close www.yahoo.com.
3. Press alt+tab to switch focus away from Google. Press alt+tab again to switch back to Google.
Expected Result: The name of the currently focused site will be announced. The name of any closed sites will not be announced.
Actual results: Chromevox announces both Google and Yahoo website titles, even though Yahoo website has been closed.