Issue 656 - Replace some __proto__ with Object.create

lib/elemHide.js

Index: lib/elemHide.js
===================================================================
--- a/lib/elemHide.js
+++ b/lib/elemHide.js
@@ -28,35 +28,35 @@ let {ElemHideException} = require("filte
 let {FilterNotifier} = require("filterNotifier");
 let {AboutHandler} = require("elemHideHitRegistration");
 let {TimeLine} = require("timeline");
 
 /**
  * Lookup table, filters by their associated key
  * @type Object
  */
-let filterByKey = {__proto__: null};
+let filterByKey = Object.create(null);
 
 /**
  * Lookup table, keys of the filters by filter text
  * @type Object
  */
-let keyByFilter = {__proto__: null};
+let keyByFilter = Object.create(null);
 
 /**
  * Lookup table, keys are known element hiding exceptions
  * @type Object
  */
-let knownExceptions = {__proto__: null};
+let knownExceptions = Object.create(null);
 
 /**
  * Lookup table, lists of element hiding exceptions by selector
  * @type Object
  */
-let exceptions = {__proto__: null};
+let exceptions = Object.create(null);
 
 /**
  * Currently applied stylesheet URL
  * @type nsIURI
  */
 let styleURL = null;
 
 /**
@@ -103,20 +103,20 @@ let ElemHide = exports.ElemHide =
     TimeLine.leave("ElemHide.init() done");
   },
 
   /**
    * Removes all known filters
    */
   clear: function()
   {
-    filterByKey = {__proto__: null};
-    keyByFilter = {__proto__: null};
-    knownExceptions = {__proto__: null};
-    exceptions = {__proto__: null};
+    filterByKey = Object.create(null);
+    keyByFilter = Object.create(null);
+    knownExceptions = Object.create(null);
+    exceptions = Object.create(null);
     ElemHide.isDirty = false;
     ElemHide.unapply();
   },
 
   /**
    * Add a new element hiding filter
    * @param {ElemHideFilter} filter
    */
@@ -300,29 +300,29 @@ let ElemHide = exports.ElemHide =
 
     TimeLine.leave("ElemHide.apply() done", "ElemHideWrite");
   },
 
   _generateCSSContent: function()
   {
     // Grouping selectors by domains
     TimeLine.log("start grouping selectors");
-    let domains = {__proto__: null};
+    let domains = Object.create(null);
     let hasFilters = false;
     for (let key in filterByKey)
     {
       let filter = filterByKey[key];
       let domain = filter.selectorDomain || "";
 
       let list;
       if (domain in domains)
         list = domains[domain];
       else
       {
-        list = {__proto__: null};
+        list = Object.create(null);
         domains[domain] = list;
       }
       list[filter.selector] = key;
       hasFilters = true;
     }
     TimeLine.log("done grouping selectors");
 
     if (!hasFilters)