I'm checking availability of the fonts specified.
* I don't find DFKai-SB nor Kaiti on my Windows 10 AU En. Do you know which versions of Windows have these fonts?
* I don't find STKaiTi-TC nor STKaiTi-SC on my Mac 10.11.6. I see STKaiti, Kaiti TC, and Kaiti SC. Was that typo? Do you know which versions of MacOS has which fonts?

*Windows 10 
Yes, I installed version 14393 with Traditional Chinese lang pack. 
Kaiti's Font name is "KAIU.ttf" now, and font family name is "標楷體".

*macOS
My fault, STKaiTi-TC / STKaiTi-SC is Postscript name. 
font family name should be "KaiTi TC" and "KaiTi SC"

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/0a4a11b1cfe0a7122fb0120672cce84e2bd78c6d

commit 0a4a11b1cfe0a7122fb0120672cce84e2bd78c6d
Author: kojii <kojii@chromium.org>
Date: Wed Nov 02 19:36:33 2016

Update the default generic font family settings for Chinese/Japanese

This patch updates the default generic font family settings for
Chinese and Japanese.

Win Japanese standard/sans-serif
Changed to Meiryo if available[1]. It was once Meiryo, but
crbug.com/506837 changed to Yu Gothic because Meiryo is not available
on non-Japanese versions of Win10.
Meiryo is preferred when available because its rendering quality is
better than Yu Gothic at this point.

Win Japanese serif
Changed to Yu Mincho if available[1].
Also added Times New Roman as fallback, since neither Yu Mincho nor MS
PMincho are available on non-Japanese versions of Win10.

Win Chinese cursive
Changed to Kaiti/DFKai-SB (SC/TC.)

Mac Chinese standard/sans-serif
Changed to PingFang SC/TC if available[1]. These fonts are available
since 10.11.

Mac Chinese cursive
Changed to Kaiti SC/TC. These are fonts available since 10.8/10.9.

[1] The first-available-font-list was added in  crbug.com/658646 

BUG= 579842 , 506837,  592199 ,  587072 ,  648256 

Review-Url: https://codereview.chromium.org/2454583002
Cr-Commit-Position: refs/heads/master@{#429366}

[modify] https://crrev.com/0a4a11b1cfe0a7122fb0120672cce84e2bd78c6d/chrome/app/resources/locale_settings_mac.grd
[modify] https://crrev.com/0a4a11b1cfe0a7122fb0120672cce84e2bd78c6d/chrome/app/resources/locale_settings_win.grd
[modify] https://crrev.com/0a4a11b1cfe0a7122fb0120672cce84e2bd78c6d/chrome/app/resources/platform_locale_settings/locale_settings_mac_zh-CN.xtb
[modify] https://crrev.com/0a4a11b1cfe0a7122fb0120672cce84e2bd78c6d/chrome/app/resources/platform_locale_settings/locale_settings_mac_zh-TW.xtb
[modify] https://crrev.com/0a4a11b1cfe0a7122fb0120672cce84e2bd78c6d/chrome/app/resources/platform_locale_settings/locale_settings_win_ja.xtb
[modify] https://crrev.com/0a4a11b1cfe0a7122fb0120672cce84e2bd78c6d/chrome/app/resources/platform_locale_settings/locale_settings_win_zh-CN.xtb
[modify] https://crrev.com/0a4a11b1cfe0a7122fb0120672cce84e2bd78c6d/chrome/app/resources/platform_locale_settings/locale_settings_win_zh-TW.xtb
[modify] https://crrev.com/0a4a11b1cfe0a7122fb0120672cce84e2bd78c6d/chrome/browser/ui/prefs/prefs_tab_helper.cc
[modify] https://crrev.com/0a4a11b1cfe0a7122fb0120672cce84e2bd78c6d/chrome/common/pref_names.cc
[modify] https://crrev.com/0a4a11b1cfe0a7122fb0120672cce84e2bd78c6d/chrome/common/pref_names.h

Appreciate your tests when available in Canary.

I have tested on Chrome Canary 55.

font-family: cursive can be shown as KaiTi. But I assigned langlocale as zh-TW, font mapped to "Kaiti SC" - for Simplified Chinese. Test page can be find on:

https://bobbytung.github.io/cursiveaskaifont/allfamilies.html

Re-opening as per #8 for further investigation.

Bobby, sorry for a long delay, I opened

https://bobbytung.github.io/cursiveaskaifont/allfamilies.html

and the "Cursive" is rendered using "Kaiti TC" for me.

Could you please double-check?