Use the correct coordinate system for drag images

-[NSDraggingItem setDraggingFrame:contents:] will treat the frame
that it’s given as being in the coordinate system of the view that has
-[NSView beginDraggingSessionWithItems:event:source:] called on it.
Therefore, make sure that the coordinates used are view coordinates,
not window coordinates.

Fixed: 1424981
Change-Id: Ib6d72770f269ef0242956c3195c99291e8322063
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4350828


Reviewed-by: Leonard Grey <lgrey@chromium.org>
Commit-Queue: Leonard Grey <lgrey@chromium.org>
Auto-Submit: Avi Drissman <avi@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1118866}