Issue 1434 - Removed remaining non-standard JavaScript code from buildtools

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/. */
 
 Cu.import("resource://gre/modules/Services.jsm");
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 
 let {addonRoot, addonName} = require("info");
 let branchName = "extensions." + addonName + ".";
 let branch = Services.prefs.getBranch(branchName);
@@ skipping 26 matching lines @@
       catch (e) {}
     }
     setter(defaultBranch, pref, value);
     defineProperty(pref, false, getter, setter);
   }
 
   // Add preference change observer
   try
   {
     branch.QueryInterface(Ci.nsIPrefBranch2).addObserver("", Prefs, true);
-    onShutdown.add(function() branch.removeObserver("", Prefs));
+    onShutdown.add(() => branch.removeObserver("", Prefs));
   }
   catch (e)
   {
     Cu.reportError(e);
   }
 }
 
 /**
  * Sets up getter/setter on Prefs object for preference.
  */
 function defineProperty(/**String*/ name, defaultValue, /**Function*/ readFunc, /**Function*/ writeFunc)
 {
   let value = defaultValue;
   Prefs["_update_" + name] = function()
   {
     try
     {
       value = readFunc(branch, name);
       triggerListeners(name);
     }
     catch(e)
     {
       Cu.reportError(e);
     }
   };
-  Prefs.__defineGetter__(name, function() value);
-  Prefs.__defineSetter__(name, function(newValue)
-  {
-    if (value == newValue)
+  Object.defineProperty(Prefs, name, {
+    get: () => value,
+    set: function(newValue)
+    {
+      if (value == newValue)
+        return value;
+
+      try
+      {
+        ignorePrefChanges = true;
+        writeFunc(branch, name, newValue);
+        value = newValue;
+        Services.prefs.savePrefFile(null);
+        triggerListeners(name);
+      }
+      catch(e)
+      {
+        Cu.reportError(e);
+      }
+      finally
+      {
+        ignorePrefChanges = false;
+      }
       return value;
-
-    try
-    {
-      ignorePrefChanges = true;
-      writeFunc(branch, name, newValue);
-      value = newValue;
-      Services.prefs.savePrefFile(null);
-      triggerListeners(name);
-    }
-    catch(e)
-    {
-      Cu.reportError(e);
-    }
-    finally
-    {
-      ignorePrefChanges = false;
-    }
-    return value;
+    },
+    enumerable: true
   });
   Prefs["_update_" + name]();
 }
 
 let listeners = [];
 function triggerListeners(/**String*/ name)
 {
   for (let i = 0; i < listeners.length; i++)
   {
     try
@@ skipping 83 matching lines @@
 {
   let str = Cc["@mozilla.org/supports-string;1"].createInstance(Ci.nsISupportsString);
   str.data = newValue;
   branch.setComplexValue(pref, Ci.nsISupportsString, str);
 }
 
 function getJSONPref(branch, pref) JSON.parse(getCharPref(branch, pref))
 function setJSONPref(branch, pref, newValue) setCharPref(branch, pref, JSON.stringify(newValue))
 
 init();