A bug in Google Chrome is causing the inbuilt antivirus scanner in the browser to initiate scans during startup causing delays in launching the program. While Google will be addressing this bug in a future patch, the only workaround right now is to clear the download history to prevent the scan from occurring at launch.
https://www.notebookcheck.net/Google-Chrome-found-to-start-antivirus-scans-at-every-launch.296696.0.html