Issue 2850 - Get rid of synchronous XMLHttpRequest on startup, embed JSON files directly instead

lib/prefs.js

 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 let {Services} = Cu.import("resource://gre/modules/Services.jsm", {});
 let {XPCOMUtils} = Cu.import("resource://gre/modules/XPCOMUtils.jsm", {});
 
 let {addonRoot, addonName} = require("info");
 let branchName = "extensions." + addonName + ".";
 let branch = Services.prefs.getBranch(branchName);
 let preconfiguredBranch =
     Services.prefs.getBranch(branchName + "preconfigured.");
 let ignorePrefChanges = false;
 
 function init()
 {
   // Load default preferences and set up properties for them
   let defaultBranch = Services.prefs.getDefaultBranch(branchName);
 
-  let request = new XMLHttpRequest();
-  request.open("GET", addonRoot + "defaults/prefs.json", false);
-  request.responseType = "json";
-  request.send();
-
-  let defaults = request.response.defaults;
-  let preconfigurable = new Set(request.response.preconfigurable);
+  let prefsData = require("prefs.json");
+  let defaults = prefsData.defaults;
+  let preconfigurable = new Set(prefsData.preconfigurable);
   for (let pref in defaults)
   {
     let value = defaults[pref];
     let [getter, setter] = typeMap[typeof value];
     if (preconfigurable.has(pref))
     {
       try
       {
         value = getter(preconfiguredBranch, pref);
       }
@@ skipping 155 matching lines @@
 // Getter/setter functions for difference preference types
 let typeMap =
 {
   boolean: [getBoolPref, setBoolPref],
   number: [getIntPref, setIntPref],
   string: [getCharPref, setCharPref],
   object: [getJSONPref, setJSONPref]
 };
 
 init();