Chrome Version       : 68.0.3440.4
OS Version: 10718.4.0

What steps will reproduce the problem?
1. Start ChromeOS
2. Observe transition from boot logo to signin screen user pods

What is the expected result?

Nice, smooth fade in of login screen over boot logo screen.

What happens instead of that?

Boot screen jumps to black screen first, then flash to white screen... then user pods show up there on white background, then finally background image shows.


Please provide any additional information below. Attach a screenshot if
possible.

See video at:

https://drive.google.com/file/d/1-0G9MUwln7nsnfWL5IMTM3aRj_7h2e6Y/view?usp=sharing

UserAgentString: Mozilla/5.0 (X11; CrOS x86_64 10718.4.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.4 Safari/537.36