Chrome Version: 72.0.3626.49/11316.66.0 dev channel Daisy,Reks,Kip
OS: Chrome

What steps will reproduce the problem?
(1)Sign in to user -> press 'Ctrl+F5(Overview Mode Button)' for screenshot -> go to Files App 
(2)Now right click on screenshot for context menu and select 'Open with Gallery' -> In Gallery select 'Print' option -> In print preview select 'Save'
(3)Now in 'Save file as' window observe unnecessary '.png' extension is seen
(Please refer Video)

Expected: Unnecessarily '.png' extension should not be seen
Actual: Instead unnecessarily '.png' extension is seen

This is Regression Issue as same is working fine on M-63

Note : Issue is also sen on M-64 To M-71 and also on M-73
 

Deleted: Actual_Extension.mp4 14.1 MB

	Actual_Extension.mp4 14.1 MB View Download

Deleted: Actual_Extension.jpg 464 KB

	Actual_Extension.jpg 464 KB View Download