chrome:flags into the address bar in any open window
Type "holding space" into the search box
"Quick access to screenshots, downloads, and files test"? << Enable it
Restart
Once it's activated, you'll see a new icon to the left of the clock and status bar in the lower-right corner of your screen. When you click it, you'll find any screenshots you've captured lately as well as any files or folders that you've pinned
Follow
Just be aware that Google is still referring to this option as a "test" — so it's always possible it may disappear