Added chrome/sidebar/content

rdf/chrome/build/registry.rdf

@@ -35,6 +35,12 @@
 
   <chrome about="chrome://sidebar/"> 
 
+    <content> 
+      <RDF:Description about="chrome://sidebar/content/">
+	    <base>resource:/res/rdf/</base>
+      </RDF:Description> 
+    </content> 
+
     <skin> 
       <RDF:Description about="chrome://sidebar/skin/">
         <base>resource:/res/rdf/</base>