TL;DR

You need to add the following parameter to block all RC4 ciphers (as of Chrome 31 in Ubuntu 12.04 with NSS 3.15)

--cipher-suite-blacklist=0x0004,0x0005,0xc011,0xc007

General Answer to figure it out yourself

The regularly updated list of all ciphers by IANA which user @Lekensteyn posted is already very helpful and definitely better than skimming some .txt files, but I have found an even easier way to...

check what ciphers your browser supports

get the hexadecimal value of the supported ciphers

Both information is provided directly in your browser by visiting the following website of the Leibniz University of Hannover:

In the picture below, the cipher indentifiers on are on the left side of the table. So, if I wanted to block the two ciphers RSA-AES-128-GCM-SHA256 and RSA-AES256-SHA I would look for (00,9c) and (00,35) .

For Google Chrome this means that I have to add the parameter1:

--cipher-suite-blacklist=0x009c,0x0035

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1- In Google Chrome on Ubuntu you have to edit the file /usr/share/applications/google-chrome.desktop and add the parameter to each line that starts with Exec=/usr/bin/google-chrome-stable . There should be three overall.