WebkitSpeech Recognition on Raspberry Pi Chromium

Question

I want to enable voice recognition on a web page that is viewed from Chromium on Raspbian. It works fine on Windows 7 / Chrome, but it does not work on Raspbian. Is it available for Chromium on Linux or not yet available?

I am using the following code:

if(!('webkitSpeechRecognition' in window)) {
    upgrade();
} else {
    var recognition = new webkitSpeechRecognition();
    recognition.continuous = true;
    recognition.interimResults = true;
    recognition.lang = Language;
    recognition.start();

    recognition.onresult = function(event) {
        console.log(event);
        for(var i = event.resultIndex; i < event.results.length; ++i) {
            if(event.results[i].isFinal) {
                lastRecognition = event.results[i][0].transcript;
                showRecognition(lastRecognition);
            }
        }
    }

    recognition.onerror = function(event) {
        console.log(event);
    }

    recognition.onend = function() {
        recognition.start();
    }
}