Index: ext/common.js
===================================================================
new file mode 100644
--- /dev/null
+++ b/ext/common.js
@@ -0,0 +1,51 @@
+/*
+ * This file is part of Adblock Plus ,
+ * Copyright (C) 2006-2014 Eyeo GmbH
+ *
+ * Adblock Plus is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * Adblock Plus is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Adblock Plus. If not, see .
+ */
+
+
+(function()
+{
+ window.ext = {};
+
+ var EventTarget = ext._EventTarget = function(cancelable)
+ {
+ this._listeners = [];
+ this._cancelable = cancelable;
+ };
+ EventTarget.prototype = {
+ addListener: function(listener)
+ {
+ if (this._listeners.indexOf(listener) == -1)
+ this._listeners.push(listener);
+ },
+ removeListener: function(listener)
+ {
+ var idx = this._listeners.indexOf(listener);
+ if (idx != -1)
+ this._listeners.splice(idx, 1);
+ },
+ _dispatch: function(cancelable, args)
+ {
+ for (var i = 0; i < this._listeners.length; i++)
+ {
+ var result = this._listeners[i].apply(null, arguments);
+ if (this._cancelable && result === false)
+ return false;
+ }
+ return true;
+ }
+ };
+})();