[MD settings] allow unicode nbsp in i18n behavior strings

ui/webui/resources/js/i18n_behavior.js

 // Copyright 2015 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.
 
 /**
  * @fileoverview
  * 'I18nBehavior' is a behavior to mix in loading of internationalization
  * strings.
  */
 
@@ skipping 28 matching lines @@
   /**
    * Returns a translated string where $1 to $9 are replaced by the given
    * values. Also sanitizes the output to filter out dangerous HTML/JS.
    * @param {string} id The ID of the string to translate.
    * @param {...string} var_args Values to replace the placeholders $1 to $9
    *     in the string.
    * @return {string} A translated, sanitized, substituted string.
    */
   i18n: function(id, var_args) {
     var rawString = this.i18nRaw_.apply(this, arguments);
-    return parseHtmlSubset('<b>' + rawString + '</b>').firstChild.innerHTML;
+    var htmlStr =
+        parseHtmlSubset('<b>' + rawString + '</b>').firstChild.innerHTML;
+    // TODO(dschuyler): use textContent rather than innerHTML; remove replace().
+    return htmlStr.replace('&nbsp;', '\u00a0');
   },
 
   /**
    * Similar to 'i18n', returns a translated, sanitized, substituted string.
    * It receives the string ID and a dictionary containing the substitutions
    * as well as optional additional allowed tags and attributes.
    * @param {string} id The ID of the string to translate.
    * @param {{substitutions: (Array<string>|undefined),
    *          attrs: (Object<function(Node, string):boolean>|undefined),
    *          tags: (Array<string>|undefined)}} opts
@@ skipping 41 matching lines @@
  * @typedef {{
  *   i18n: function(string, ...string): string}},
  *   i18nAdvanced: function({
  *     substitutions: (Array<string>|undefined),
  *     attrs: (Object<function(Node, string):boolean>|undefined),
  *     tags: (Array<string>|undefined)}, opts),
  *   i18nExists: function(string)
  * }}
  */
 I18nBehavior.Proto;