Translate: enable against unknown languages with server side detection

chrome/browser/resources/translate.js

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This code is used in conjunction with the Google Translate Element script.
 // It is injected in a page to translate it from one language to another.
 // It should be included in the page before the Translate Element script.
 
 var cr = {};
 
@@ skipping 112 matching lines @@
      * @type {boolean}
      */
     get error() {
       return error;
     },
 
     /**
      * 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();
     },
 
     /**
      * Time in msec from this script being injected to all server side scripts
      * being loaded.
      * @type {number}
      */
     get loadTime() {
       if (loadedTime == 0)
@@ skipping 60 matching lines @@
       } catch (err) {
         error = true;
         return;
       }
       // The TranslateService is not available immediately as it needs to start
       // Flash.  Let's wait until it is ready.
       checkLibReady();
     }
   };
 })/* Calling code '(|key|);' will be appended by TranslateHelper in C++ here. */