There's a closed pull request on the void-packages repository

[WIP] chromium: update to 89.0.4389.72
https://github.com/void-linux/void-packages/pull/29205

Description:
CVE-2021-21166

+ x86_64 patch set updated, built, tested very cursory and seems to work
+ i686 patch applies w/o change, built, cursory test in a VM
+ x86_64-musl patch set updated, built, works but can crash, see comments below
+ system opus disabled because the generated shim header opus.h tries to include <opus.h> and fails
+ not sure if libc_malloc.patch is ok, i.e. simply use malloc() instead of __libc_malloc().
+ more to do

[ci skip]

If you don't want to build yourself my repo has the update for testing.