Google-chrome – Proxy for Google Chrome

Google's help docs show how to do this:

1. Click the wrench menu tools menu.

   

2. Select Options.
3. Click the Under the Hood tab.
4. In the 'Network' section, click the Change proxy settings button. This will open the 'Internet Properties' dialog box in Windows where you can adjust your network settings. See here for more details.

You can use the Chromium proxy settings from the command line. The man page tells you how. So here is an excerpt from man chromium-browser from my Ubuntu Natty:

   --proxy-server=host:port
          Specify the HTTP/SOCKS4/SOCKS5 proxy server to use for requests.  This overrides any environment variables or settings picked via the options dialog.  An individual
          proxy server is specified using the format:

            [<proxy-scheme>://]<proxy-host>[:<proxy-port>]

          Where <proxy-scheme> is the protocol of the proxy server, and is one of:

            "http", "socks", "socks4", "socks5".

          If the <proxy-scheme> is omitted, it defaults to "http". Also note that "socks" is equivalent to "socks5".

          Examples:

            --proxy-server="foopy:99"
                Use the HTTP proxy "foopy:99" to load all URLs.

            --proxy-server="socks://foobar:1080"
                Use the SOCKS v5 proxy "foobar:1080" to load all URLs.

            --proxy-server="sock4://foobar:1080"
                Use the SOCKS v4 proxy "foobar:1080" to load all URLs.

            --proxy-server="socks5://foobar:66"
                Use the SOCKS v5 proxy "foobar:66" to load all URLs.

          It is also possible to specify a separate proxy server for different URL types, by prefixing the proxy server specifier with a URL specifier:

          Example:

            --proxy-server="https=proxy1:80;http=socks4://baz:1080"
                Load https://* URLs using the HTTP proxy "proxy1:80". And load http://*
                URLs using the SOCKS v4 proxy "baz:1080".

The advantage of using the command line arguments is, that you do not have to change your global system settings.

For example:

$ chromium-browser --proxy-server="http://127.0.0.1:8080"

Also have a look at Justin's post in this thread where he describes how to use the proxy for DNS request also.