UserAgent: Mozilla/5.0 (X11; CrOS x86_64 11021.19.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.22 Safari/537.36
Platform: 11021.19.0 (Official Build) beta-channel cyan

Steps to reproduce the problem:
1. No clue - last crash happened while searching chrome://settings; can't find a consistent pattern.
2. 
3. 

What is the expected behavior?

What went wrong?
Entire system crashed and Chrome restarts.

Crashed report ID: 1023282731671a7c

How much crashed? Whole browser

Is it a problem with a plugin? N/A 

Did this work before? N/A 

Chrome version: 70.0.3538.22  Channel: beta
OS Version: 11021.19.0
Flash Version: 31.0.0.113 

I'm getting crash reports every few minutes. Most of them happened in the middle of the night when I was asleep (unless the crash report time isn't using the correct time zone) so I wasn't even at the Chromebook doing anything. Here are a few of the many report IDs:
b4a8a5bfddea2014
6 minutes later: e7b4390373375b02
2 minutes later: d73f07f3df92f943
8 minutes later: 30c99c669391be02
1 minute later: 588a1b8626853973
6 minutes later: a8795c3ada9670de

Followed by many more but hopefully these will help in identifying the crash source.