Bug 431003 bustage fix for Firefox

content/html/document/test/test_bug369370.html

@@ -88,7 +88,11 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=369370
 
         kidWin.close();
         netscape.security.PrivilegeManager.enablePrivilege('UniversalXPConnect');
-        prefs.clearUserPref("browser.enable_automatic_image_resizing");
+        try {
+          prefs.clearUserPref("browser.enable_automatic_image_resizing");
+        } catch (ex) {
+          // throws if it wasn't already set because app default was true
+        }
         SimpleTest.finish();
     }