Google Chrome	63.0.3239.50 (Official Build) beta (64-bit)
Revision	0
Platform	10032.39.0 (Official Build) beta-channel samus

What steps will reproduce the problem?
(1) mount several large files using a file handler (for instance, download gigabyte sized Chrome OS images from goldeneye .xz files, open them using the "Wicked Good Unarchiver")
(2) visit chrome://restart to trigger browser restart
(3) load Files app

What is the expected result?

Files app is usable

What happens instead?

Files app is largely empty until the file handler is done mounting, notifications appear saying that those operations are taking a long time