Chrome 57.0.2985.0

- Open DevTools with persistence experiment on, and open a folder.
- In Sources, open a mapped file (green dot) and an unmapped file
- Select/open the tab with the mapped file
- Refresh the page a couple of times

Expected
Since the mapped file was the last used file, it should be open by default

Expected
After a few refreshed, the unmapped file is opened by default.  Seems to be that the mapped file loads later asynchronously, and we are not trying to restore focus to it then.