UserAgent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/49.0.2623.75 Safari/537.36

Example URL:
youtube.com

Steps to reproduce the problem:
1. In windows 10 (Chinese verison) open YouTube with chrome, with YouTube language preference set to English.

What is the expected behavior?
1. Chinese characters in video titles are rendered correctly
2. Typing Chinese in the YT search box should render them correctly

What went wrong?
Most Chinese characters are rendered as squares.

Does it occur on multiple sites: N/A

Is it a problem with a plugin? No 

Did this work before? Yes I haven't have any Chinese character issue in chrome with more than 10 years.

Does this work in other browsers? Yes 

Chrome version: 49.0.2623.75  Channel: stable
OS Version: 10
Flash Version: 

This is my original email sent to eng-misc:

==========================================
Hi all,

I found an issue with Chinese character rendering of YouTube on Chrome only.

Symptom: (most) Chinese characters are rendered as a square.
Both Simplified and Traditional Chinese characters are affected.
By "most" I mean in the same text line there might be, for example, 8 squares and 2 correctly rendered character.
The few correctly rendered characters are all the same character.
Typing Chinese into YouTube search box shows the same rendering behavior.

Environment:
OS: windows 10 (Chinese version)
browser: chrome 48.0.2564.116 m
It only happens on my personal computer, not on my corp laptop which runs windows 7.
It also does NOT affect firefox and IE in my personal computer.

Workaround:
Changing the language preference from "English" to "Chinese" would fix it.
It appears that Chinese characters of YouTube on chrome now only render correctly if language if set to one of the 3 "Chinese" option.

Some facts:
The page detects UTF-8 encoding correctly.
View page source would show Chinese correctly.
Incognito mode does not help.
My chrome just gets updated when I was typing this email. Not fixed.