Font rendering and "lang" attribute

[luixxiul]

Describe the issue you encountered:
Font rendering is poor in Japanese if "lang" attribute is not set properly in html tag.

Japanese and Chinese fonts are mixed here. For example "しています" rendered in Japanese fonts, while the font for "説明" is in Chinese (Taiwan) fonts.

Basically this bug seems to be like https://bugs.chromium.org/p/chromium/issues/detail?id=422180 "Chinese font selected under Japanese locale on Android".

Because this bug does not occur on Chrome, we should be able to fix this.

Expected behavior: It should be like this:

• Platform (Win7, 8, 10? macOS? Linux distro?):
• Brave Version:
• Steps to reproduce:
  1. Open https://braveinfo.net
  2. Open Devtool
  3. Change font-family to Arial for :root
  4. Replace lang="ja" into lang="en"
• Screenshot if needed:
• Any related issues: Localization tracking bug #1858

[luixxiul]

This applies not only page rendering, but also frame rendering.

1. Make sure any Japanese fonts are installed on your machine
2. Open Devtool with Shift+F8
3. Change en-US of html lang into ja-JP en-US

This makes it into this, which looks consistent:

[luixxiul]

The issue seems to be specific to Windows. On macOS it looks fine. I did not test on Linux.

[luixxiul]

It seems this was fixed with the latest cr54.

@bridiver do you have any info on this?

[bridiver]

this was probably related to the general locale issues so it would have been fixed by brave/muon@d4f451c

[luixxiul]

Test plan: available on the 1st post.