Bug: Focusing duplicates of tabs when prompted to save changes

[tbrockman]

Describe the bug
When we attempt to close a tab that intercepts the close event and prompts to deal with any unsaved changes, we don't attempt to focus the correct tab after the dialog is handled.

To Reproduce
This seems to happen pretty reliably with gmail, might be able to reproduce by navigating to https://mail.google.com/mail/u/0/#inbox?compose=new in two separate tabs.

Expected behavior
Regardless of user selection, we could focus the original tab.