Font hinting is lost in Chrome-like browsers (for some languages )

Solution 1:

The fix:

sudo nano /etc/fonts/conf.avail/69-language-selector-ja.conf

change on line 8 family to lang

<test qual="all" name="lang" compare="contains">

TL;DR:

I began the test with replacing all Ubuntu *.conf files in the /etc/fonts/conf.d directory with Manjaro's to test whether it was a config bug (I thought it was in the freetype library). New configs worked well. Further investigating revealed that the specific issue is in the /etc/fonts/conf.avail/69-language-selector-ja.conf file. This file had at line 8

<test qual="all" name="family" compare="contains">

which seems to be wrong, since the family was already selected. It should be lang instead. Editing line 8 fixes all the annoyance.

<test qual="all" name="lang" compare="contains">

Hope, it will help some people like me. I filed a bug report in launchpad here. I encourage people to test the bug and click on "This bug affects me" link if this answer helped you.