Google Chrome	66.0.3336.6 (Official Build) canary (64-bit) (cohort: 64-Bit)
Windows 10 Enterprise Version 1607 Build 14393.2007
NVDA 2017.4
JAWS 2018.1801.81 ILM 

This is related to a webpage authoring issue, this is not screen reader dependent. Both screen readers behaved the same so for simplicity, I'll just report the experience.

Steps to repro:

Go to any of these Chrome Download pages:
https://www.google.com/chrome/browser/desktop/index.html
https://www.google.com/chrome/browser/desktop/index.html?extra=devchannel&platform=win64
https://www.google.com/chrome/browser/canary.html
https://www.google.com/chrome/browser/beta.html

After pressing the download button on any of those sites, you're brought to the EULA.

Expected: the close button is properly labeled as a button labeled Close
Actual: Close button is unlabeled. It's read as "index link"