4- Add the following code after “language_picker”> :
{option id=”ar” value=”ar”}Arabic{/option}

replace all { bye because I can’t write them here!

I don’t know if it is legal or not but to have Arabic just do the following steps:
1- Install the dectionary from link: https://chrome.google.com/extensions/detail/mgijmajocgfcbeboacabfgobmjgjcoja

2- Open installation folder, It will be here (replace XXXX by your user name):
C:\Documents and Settings\XXXXX\Local Settings\Application Data\Google\Chrome\User Data\Default\Extensions\mgijmajocgfcbeboacabfgobmjgjcoja\2.0.4_0

3- Open File (options.html) with notepad.

4- Add the following after after :
Arabic

5- Save and close.

6- now if you go to extension options you’ll find arabic there.

7- Enjoy Translation.

Note: this can be done for any language but should be available at file (lang_map_js_min.js) which available in the same folder.