Is there an associated issue that this PR fixes?

Is there an associated issue that this PR fixes?

Not at all, it's more a code improvement than a bugfix since no issue can be reproduced in VSCode but it may impact forks and custom builds

Should I still create an issue?

But how can we hard-code a reference to document.body when the parent of the workbench might be something else? I am worried about regressions here actually, but I also do not fully understand the issue yet. If there is a repro, that would help.

Note that your change impacts not only web but also VS Code for desktop.

But how can we hard-code a reference to document.body when the parent of the workbench might be something else?

In fullscreen mode, the parent doesn't really matter as it doesn't impact the container size at all, so it doesn't make sense to measure it to layout the container

I am worried about regressions here actually

In both cases (web.main.ts and desktop.main.ts) the given parent is mainWindow.document.body so I don't think it can actually change anything

but I also do not fully understand the issue yet. If there is a repro, that would help.

It's not simple to provide a repro

I'm integrating VSCode oss in a webpage between a header and a footer. Here's the result in fullscreen (an empty area at the bottom whose size is the height of the footer and the header combined):

Note that your change impacts not only web but also VS Code for desktop.

Indeed, I was confused by the browser directory