There's another user who are using Chromebook.

Chromebook 11 Poin2
Chrome O.S. 53.0.2785.103
Symptoms 
1) Align function errors
2) Line error 
3) Broken letters when putting some words in written sentences
4) Formatting errors when using numbered list

https://drive.google.com/file/d/0B5tFwOx-ZOLUb3dReWMxcTc1QVk/view

The user posted up this problem on KO Chrome Forum:
https://productforums.google.com/forum/#!category-topic/chrome-ko/%EC%A0%9C%EC%95%88-%EB%B0%8F-%EC%9D%98%EA%B2%AC/UuuV4iEWygY

What is most helpful for these kinds of bugs is a sample Docs doc and an exact set of steps to reproduce the problem with that doc. The steps should specify exactly what should be typed (e.g. I'm not sure what's meant by a "full stop" - it would be better to specify exactly what to type to create the full stop). Screenshots are also helpful as far as showing what the problem is vs. what should actually be occurring.

I doubt this can be a Chrome issue. It's most likely to be a Doc issue. 

A 'full stop' is 'period' ( regular ASCII period). 

I doesn't matter what's typed exactly. Any random gibberish Hangul with a period in the middle of a line should reproduce this bug. 

http://www.fileformat.info/info/unicode/char/2e/index.htm : U+002E's Unicode charater name is 'Full Stop' :-) 

With my gmail account, I can reproduce it, but I can't reproduce it with my google.com account. So, it's likely that the issue (Google Docs) was fixed recently. 

Anyway, regardless of this issue, Korean line breaking has been broken for ages in Google Docs.  

Filed an internal bug: b/31889843

re comment 7: actually, regardless of which Google account I use, I can reproduce this bug so that it's still an outstanding issue even for the latest live version of Google docs, I'm afraid. 

The internal bug was fixed and I confirmed that it's fixed for me, too. 

songsuk@: can you verify (once more)? thanks 

Still reproduce the issue on Mac/CrOS.  Will verify it once the fix is ready.

>>> This fix will hit corp Wed 10/5 and prod next Mon 10/10.

> I confirmed that it's fixed for me, too

The above statement in comment 11 was a bit premature. 

Thanks, songsuk !

Thanks all, I found that it worked out for Mac OS. users. However, the Chromebook user who was mentioned on my comment 3 still has trouble with it as below. FYI.      

Chromebook 11 Poin2
Chrome O.S. 53.0.2785.103

https://screenshot.googleplex.com/CX0DUvK5TxW

There's one more Mac OS. user here. FYI.

https://productforums.google.com/forum/#!category-topic/chrome-ko/%EB%AC%B8%EC%A0%9C%ED%95%B4%EA%B2%B0-%EB%B0%A9%EB%B2%95/7KnY_Of3GH8

Verified it on chrome 53.0.2785.143- Mac10.12,  Chrome53.0.2785.144/CrOS8530.93-Daisy