Issue 656 - Replace some __proto__ with Object.create

lib/utils.js

Index: lib/utils.js
===================================================================
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -534,17 +534,17 @@ let Utils = exports.Utils =
 /**
  * A cache with a fixed capacity, newer entries replace entries that have been
  * stored first.
  * @constructor
  */
 function Cache(/**Integer*/ size)
 {
   this._ringBuffer = new Array(size);
-  this.data = {__proto__: null};
+  this.data = Object.create(null);
 }
 exports.Cache = Cache;
 
 Cache.prototype =
 {
   /**
    * Ring buffer storing hash keys, allows determining which keys need to be
    * evicted.
@@ -588,17 +588,17 @@ Cache.prototype =
   },
 
   /**
    * Clears cache contents.
    */
   clear: function()
   {
     this._ringBuffer = new Array(this._ringBuffer.length);
-    this.data = {__proto__: null};
+    this.data = Object.create(null);
   }
 }
 
 // Getters for common services, this should be replaced by Services.jsm in future
 
 XPCOMUtils.defineLazyServiceGetter(Utils, "categoryManager", "@mozilla.org/categorymanager;1", "nsICategoryManager");
 XPCOMUtils.defineLazyServiceGetter(Utils, "ioService", "@mozilla.org/network/io-service;1", "nsIIOService");
 XPCOMUtils.defineLazyServiceGetter(Utils, "promptService", "@mozilla.org/embedcomp/prompt-service;1", "nsIPromptService");