Version: ALL
OS: Chrome OS

What steps will reproduce the problem?
(1)  Connect 2 monitors to a Chrome device (1xHDMI + 1xDP on Chromebox, or 1 built in on Chromebase + external HDMI)
(2)  Verify expanded desktop works properly, and that monitor arrangement/rotation works correctly in Display Settings
(3)  Arrange the monitors in portrait mode, one column, two rows (on top of each other).
(4)  Enable unified desktop mode
(5a)  In stable - You will see a mangled output, with half of each display blank and odd cursor interaction (movement to one edge loops back to the opposite edge endlessly, never reaching the second display).  Resolution shows as 2160x1920 regardless of arrangement.
(5b) In dev - Crash

What is the expected output? What do you see instead?

We expect to be able to rotate and arrange monitors as needed.  The display settings dialog will allow us to arrange and use them before enabling unified desktop.  When unified desktop is enabled, we lose the ability to arrange the monitors, and monitors that were previously arranged in expanded mode display mangled output.  On Dev, it just crashes when attempting to enable unified desktop with rotated monitors and reverts to expanded desktop.