This tells Chrome to use a custom proxy configuration. You can specify a custom proxy configuration in three ways:1) By providing a semi-colon-separated mapping of list scheme to url/port pairs. For example, you can specify: --proxy-server="http=foopy:80;ftp=foopy2" to use HTTP proxy "foopy:80" for http URLs and HTTP proxy "foopy2:80" for ftp URLs.2) By providing a single uri with optional port to use for all URLs. For example: --proxy-server="foopy:8080" will use the proxy at foopy:8080 for all traffic. 3) By using the special "direct://" value. --proxy-server="direct://" will cause all connections to not use a proxy.