Fix some nits.

extensions/firefox/components/PdfStreamConverter.js

@@ -22,18 +22,24 @@ function log(aMsg) {
   Services.console.logStringMessage(msg);
   dump(msg + '\n');
 }
-function getWindow(top, id) top.QueryInterface(Ci.nsIInterfaceRequestor)
+function getWindow(top, id) {
+  return top.QueryInterface(Ci.nsIInterfaceRequestor)
             .getInterface(Ci.nsIDOMWindowUtils)
             .getOuterWindowWithId(id);
-function windowID(win) win.QueryInterface(Ci.nsIInterfaceRequestor)
+}
+function windowID(win) {
+  return win.QueryInterface(Ci.nsIInterfaceRequestor)
             .getInterface(Ci.nsIDOMWindowUtils)
             .outerWindowID;
-function topWindow(win) win.QueryInterface(Ci.nsIInterfaceRequestor)
+}
+function topWindow(win) {
+  return win.QueryInterface(Ci.nsIInterfaceRequestor)
             .getInterface(Ci.nsIWebNavigation)
             .QueryInterface(Ci.nsIDocShellTreeItem)
             .rootTreeItem
             .QueryInterface(Ci.nsIInterfaceRequestor)
             .getInterface(Ci.nsIDOMWindow);
+}
 let application = Cc['@mozilla.org/fuel/application;1']
                     .getService(Ci.fuelIApplication);
 let privateBrowsing = Cc['@mozilla.org/privatebrowsing;1']