https://code.google.com/chrome/webstore/docs/i18n.html
links to
http://code.google.com/chrome/extensions/i18n.html
which states that these are the supported locales:
am ar bg bn ca cs da de el en en_GB en_US es es_419 et fi fil fr gu he
hi hr hu id it ja kn ko lt lv ml mr nl or pl pt pt_BR pt_PT ro ru sk
sl sr sv sw ta te th tr uk vi zh zh_CN zh_TW
https://chrome.google.com/webstore/developer/edit/[webappid]
offers these Locales:
United States, Argentina, Australia, Brazil, Canada, France, Germany,
India, Italy, Japan, Mexico, Netherlands, Poland, Portugal, Spain,
United Kingdom
I zipped up my app folder with the /_locales/es_419/ folder (and
several other locale folders, including es), and uploaded it. All the
other locales appear in the "Developer dashboard > Edit item >
Currently editing language" dropdown at the top of the page, but the
only spanish is "español", corresponding to the es locale.
I tried different folder names: es-419, es_AR, es_MX, but those didn't
work. I also tried es_419 with es changed to es_ES (since Portuguese
uses pt_PT, not just pt), but then español disappeared.
Am I doing something wrong, or is this not supported yet?