UserAgent: Mozilla/5.0 (X11; CrOS x86_64 9086.0.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/57.0.2951.0 Safari/537.36

Steps to reproduce the problem:
1. Boot Dell Chromebook 13
2. Attach Dell P4317Q to Chromebook HDMI
3. Go to SETTINGS | DISPLAY | P4317Q
3a. Resolution is show as 3840x2160 (Best) (text looks HUGE, obviously this is 2x-DPI)
3b. ACTUAL outputted resolution is 1920x1080 (2x)
4. Change resolution drop down to 1920x1080 (2x)
4a. No resolution change occurs... because its not actually changed. (no monitor "flicker")
5. Change resolution drop down BACK to 3840x2160
5a. At this point, the device is NOW ACTUALLY outputting 3840x2160 (monitor flicker and obvious DPI change)

Step 6. Shutdown chromebook & restart - my settings I applied in 5a are now back at 3b.

What is the expected behavior?
If CrOS is going to auto-detect a high res monitor and display in 2x DPI - the OS settings control panel should properly reflect that.

Specific resolution / DPI settings should persist through sleep mode or reboots.

What went wrong?
4k monitor resolution incorrectly being reported as 1x-DPI when it is actually 2x-DPI

4K 1x-DPI setting must be reapplied after every sleep mode or reboot.

Did this work before? N/A 

Chrome version: 57.0.2951.0  Channel: dev
OS Version: 9086.0.0
Flash Version: Shockwave Flash 24.0 r0

I can reproduce this 100% of time.
 

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