What is the minimum chrome version required for chrome.extension.sendMessage?
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I tried using chrome.extension.sendMessage in my extension and upset a lot of users who weren't on the same Chrome version as me (v20.0.1132.47). I tried looking at the documentation here - http://code.google.com/chrome/extensions/extension.html#method-sendMessage but there is nothing indicating when this method was introduced.

Compare this to the isAllowedIncognitoAccess method which *clearly* states "This function was added in version 12.0.706.0. If you require this function, the manifest key minimum_chrome_version can ensure that your extension won't be run in an earlier browser version."

Does anyone know what the minimum Chrome version is to use this method?