ChromeOS version: 70+
ChromeOS device model: any
Case#: 17533780

Description:
With introduction of Managed Guest sessions in 70, behavior of DeviceLocalAccountAutoLoginDelay changed:

Steps to reproduce: 
1. Set DeviceLocalAccountAutoLoginDelay to 30000 (30s)
2. Once device starts, click on "Add person" and constantly type

Current Behavior / Reproduction: 
Regardless of anything, public session starts after 30 seconds, per 70_bad.mp4 on versions 70 and +

Expected Behavior: 
30-second timer of DeviceLocalAccountAutoLoginDelay starts actually after user stops typing, per 69_good.mp4 on versions 69 and -

Drive link to logs: 
https://drive.google.com/open?id=1i6z-hnPFSHZapzrG_pUMSY55lsff1Wsg

Considering this as regression, as old behavior is much better for user experience.