WebUI: Update some more uses of the old-style i18ntemplate/LocalStrings.

ui/webui/resources/js/load_time_data.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.
 
 /**
  * @fileoverview This file defines a singleton which provides access to all data
  * that is available as soon as the page's resources are loaded (before DOM
  * content has finished loading). This data includes both localized strings and
  * any data that is important to have ready from a very early stage (e.g. things
  * that must be displayed right away).
  */
 
 var loadTimeData;
 
 // Expose this type globally as a temporary work around until
 // https://github.com/google/closure-compiler/issues/544 is fixed.
 /** @constructor */
 function LoadTimeData() {}
 
 (function() {
   'use strict';
 
   LoadTimeData.prototype = {
     /**
      * Sets the backing object.
+     *
+     * Note that there is no getter for |data_| to discourage abuse of the form:
+     *
+     *     var value = loadTimeData.data()['key'];
+     *
      * @param {Object} value The de-serialized page data.
      */
     set data(value) {
       expect(!this.data_, 'Re-setting data.');
       this.data_ = value;
     },
 
     /**
+     * Returns a JsEvalContext for |data_|.
+     * @returns {JsEvalContext}
+     */
+    createJsEvalContext: function() {
+      return new JsEvalContext(this.data_);
+    },
+
+    /**
      * @param {string} id An ID of a value that might exist.
      * @return {boolean} True if |id| is a key in the dictionary.
      */
     valueExists: function(id) {
       return id in this.data_;
     },
 
     /**
      * Fetches a value, expecting that it exists.
      * @param {string} id The key that identifies the desired value.
@@ skipping 91 matching lines @@
    * @param {string} type The type we expect |value| to be.
    */
   function expectIsType(id, value, type) {
     expect(typeof value == type, '[' + value + '] (' + id +
                                  ') is not a ' + type);
   }
 
   expect(!loadTimeData, 'should only include this file once');
   loadTimeData = new LoadTimeData;
 })();