Disable code linkify and whitespace showing for very long files and pages #3218

Example URL please, as the issue template suggested.

This one for example https://github.com/aminya/SnoopCompile.jl/pull/1/files The scrolling gets jumpy. or this https://github.com/timholy/SnoopCompile.jl/pull/71/files

Most features affect the loading time because they apply their changes all at once — This could be be linkify-code — and don't affect the scrolling once that's done (it's only a handful of changes usually)

show-whitespace is one of the most intensive features, which is why it was modified to only act on a few lines at a time to avoid locking the document at the beginning.

This is probably the only feature that could affect the scrolling performance, but I don't personally notice any differences in scrolling in neither browser (my notebook is from 2013)

Do you have any other extensions running?

I can test using a safe mode setup with refined Github only and then will return back to you.