Issue 1708 - Integrate first-run page changes in Chrome/Opera/Safari

ext/background.js

Index: ext/background.js
===================================================================
--- a/ext/background.js
+++ b/ext/background.js
@@ -17,27 +17,31 @@
 
 (function()
 {
   var nonEmptyPageMaps = {__proto__: null};
   var pageMapCounter = 0;
 
   var PageMap = ext.PageMap = function()
   {
-    this._map = {__proto__: null};
+    this._map = Object.create(null);
     this._id = ++pageMapCounter;
   };
   PageMap.prototype = {
     _delete: function(id)
     {
       delete this._map[id];
 
       if (Object.keys(this._map).length == 0)
         delete nonEmptyPageMaps[this._id];
     },
+    keys: function()
+    {
+      return Object.keys(this._map).map(ext._getPage);
+    },
     get: function(page)
     {
       return this._map[page._id];
     },
     set: function(page, value)
     {
       this._map[page._id] = value;
       nonEmptyPageMaps[this._id] = this;