remove redundant code for seamonkey, especially given that it doesn't work in embedding. allows embedding apps to use xul pref window. r=blake/sr=hyatt/a=asa. bug# 128924.

xpfe/components/prefwindow/resources/content/pref.xul

@@ -31,19 +31,6 @@
    **/
   function Startup()
     {
-      // Check for an existing pref window.
-      const kWindowMediatorContractID = "@mozilla.org/rdf/datasource;1?name=window-mediator";
-      const kWindowMediatorIID = Components.interfaces.nsIWindowMediator;
-      const kWindowMediator = Components.classes[kWindowMediatorContractID].getService(kWindowMediatorIID);
-      var windows = kWindowMediator.getEnumerator("mozilla:preferences");
-      var prefWindow;
-      while ((prefWindow = windows.getNext().QueryInterface(Components.interfaces.nsIDOMWindow)) &&
-              prefWindow != window) {
-        // Prefs already open, activate it and close this one.
-        prefWindow.focus();
-        window.close();
-      }
-
       hPrefWindow = new nsPrefWindow('panelFrame');  
       
       if( !hPrefWindow )