Use chrome URLs. Fix for bug #6369.

rdf/resources/sidebar-browser.xul

@@ -1,6 +1,6 @@
 <?xml version="1.0"?>
-<?xml-stylesheet href="resource:/res/samples/xul.css" type="text/css"?>
-<?xml-stylesheet href="resource:/res/rdf/sidebar.css" type="text/css"?>
+<?xml-stylesheet href="chrome://global/skin/" type="text/css"?>
+<?xml-stylesheet href="chrome://sidebar/skin/" type="text/css"?>
 
 <!DOCTYPE window
 [