UserAgent: Mozilla/5.0 (X11; CrOS x86_64 10895.78.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.120 Safari/537.36
Platform: 10895.78.0 (Official Build) stable-channel eve

Steps to reproduce the problem:
1. Play Tenhou via the Android App (https://play.google.com/store/apps/details?id=net.tenhou.WebBrowser20161220&hl=en_US) on ChromeOS a lot
2. Switching back and forth between browser and app windows seems to contribute to the bug, but doesn't seem to be necessary.
3. Do this a bunch until it happens.

What is the expected behavior?
The OS continues to operate normally.

What went wrong?
Occasionally the OS becomes entirely unresponsive. The screen has small, thick black bars drawn at regular intervals, forming a diagonal pattern across the screen. Otherwise the display is just frozen.

The only solution I have found is to reboot.

Crashed report ID: No, none is generated

How much crashed? Whole browser

Is it a problem with a plugin? N/A 

Did this work before? No 

Chrome version: 69.0.3497.120  Channel: n/a
OS Version: 10895.78.0
Flash Version: 

Because the OS freezes, no crash report appears to generate.