Chrome Version: 71.0.3578.94 (Official Build) (64-bit)
Chrome OS Version: 11151.59.0 (Official Build) stable-channel nocturne
Chrome OS Platform: Pixel Slate

Steps To Reproduce:
(1) Open an image in Files.
(2) Tap Crop.
(3) Set aspect ratio to 1x1 and then back to free.  (See crbug.com/917940.)
(4) Touch-drag the top left corner.

Expected Result:
The top left corner of the frame is draggable.

Actual Result:
If the frame is at the top of the image, the top corners are not draggable.  If the frame is not at the top, trying to drag a top corner might make the bottom corner move.

How frequently does this problem reproduce? (Always, sometimes, hard to
reproduce?)
When the frame is at the top of the image, always, on both Link and Nocturne.

What is the impact to the user, and is there a workaround? If so, what is
it?
Frustration.