The source is public and the version history too, so you don't need to assume, you can look. If you don't see anything particular, you may assume that it's a bug and wasn't easily visible to the developers either.
This will most likely be a patch the product bits pf Chrome, not chromium. The bug isn't in Edge.
Here's the fix, the bug is in chromium but only affects chrome because it has some "Hosted Apps" installed out of the box.
You are talking about Chrome or Chromium?
When I looked at the source, around 2015, there wasn't much difference, other than the name. People called "Google" were allowed to name the result of building it "Chrome". If you weren't Google you had to call it Chromium, and could of course apply patches or change the build flags. The functional differences I saw then were all a result of patches that were applied by my distribution.