Translate: enable against unknown languages with server side detection

chrome/browser/resources/translate.js

Index: chrome/browser/resources/translate.js
diff --git a/chrome/browser/resources/translate.js b/chrome/browser/resources/translate.js
index 07f7113c19098a9aa32ea8a556b26f867bc9702e..df7437be1dc7b2bb9af5b190c2240f6e5e082731 100644
--- a/chrome/browser/resources/translate.js
+++ b/chrome/browser/resources/translate.js
@@ -130,11 +130,15 @@ cr.googleTranslate = (function(key) {
      * The language the page translated was in. Is valid only after the page
      * has been successfully translated and the original language specified to
      * the translate function was 'auto'. Is empty otherwise.
+     * Some versions of Element library don't provide |getDetectedLanguage|
+     * function. In that case, this function returns 'und'.
      * @type {boolean}
      */
     get sourceLang() {
       if (!libReady || !finished || error)
         return '';
+      if (!lib.getDetectedLanguage)
+        return 'und'; // defined as chrome::kUnknownLanguageCode in C++ world.
       return lib.getDetectedLanguage();
     },