Flesh out the location-page class to make it more general.

chrome/browser/resources/settings/languages_page/languages.js

Index: chrome/browser/resources/settings/languages_page/languages.js
diff --git a/chrome/browser/resources/settings/languages_page/languages.js b/chrome/browser/resources/settings/languages_page/languages.js
index 33141369cf5d2523a843ea1bfa704deafa3713fa..8f033e9fd52c81fe1c647f9f2b4b1ad49d22083f 100644
--- a/chrome/browser/resources/settings/languages_page/languages.js
+++ b/chrome/browser/resources/settings/languages_page/languages.js
@@ -191,6 +191,7 @@ var preferredLanguagesPrefName = cr.isChromeOS ?
  */
 Polymer({
   is: 'settings-languages-singleton',
+  behaviors: [PrefsBehavior],
 
   properties: {
     /**
@@ -405,29 +406,6 @@ Polymer({
   },
 
   /**
-   * Gets the pref at the given key. Asserts if the pref is not found.
-   * @param {string} key
-   * @return {!chrome.settingsPrivate.PrefObject}
-   */
-  getPref_: function(key) {
-    var pref = /** @type {!chrome.settingsPrivate.PrefObject} */(
-        this.get(key, this.prefs));
-    assert(typeof pref != 'undefined', 'Pref is missing: ' + key);
-    return pref;
-  },
-
-  /**
-   * Sets the value of the pref at the given key. Asserts if the pref is not
-   * found.
-   * @param {string} key
-   * @param {*} value
-   */
-  setPrefValue_: function(key, value) {
-    this.getPref_(key);
-    this.set('prefs.' + key + '.value', value);
-  },
-
-  /**
    * Deletes the given item from the pref at the given key if the item is found.
    * Asserts if the pref itself is not found or is not an Array type.
    * @param {string} key