Chrome Version       : 59.0.3071.47
OS Version: 9460.34.0 (Official Build) beta-channel elm

What steps will reproduce the problem?
1. Install beta channel on Acer Chromebook R13
2. Fold screen flat to use tablet mode
3. Try to rotate screen

What is the expected result?
Screen should rotate from 0 - 90 - 190 - 270 degrees

What happens instead of that?
Nothing. Screen stays at 0 degrees


Please provide any additional information below. Attach a screenshot if
possible.
Works fine in stable channel. You can manually rotate the screen in tablet mode via Settings > Display > Rotation



UserAgentString: Mozilla/5.0 (X11; CrOS aarch64 9460.34.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.47 Safari/537.36