This is a bit disingenuous. If you install Chrome, you install Chrome and all it's parts. They don't ask your consent for individual parts because that would be absurd. If you don't want Chrome and all its parts, don't use it.
This is not a reasonable size for something that's "just another part of Chrome", this blows up the file size by many times
If I install Chrome, I expect it to take a few hundred MBs and then only take up additional space in a controlled and transparent manner - for its cache, for example. For me, secretly adding 4GB after installation is a bit too much.
If you're okay with 4GB being added, where would you draw a line? What if it downloaded a 40GB file? 400GB?