Align whitelisting behavior in Chrome with Firefox

background.js

Index: background.js
===================================================================
--- a/background.js
+++ b/background.js
@@ -46,17 +46,18 @@ function setDefaultOptions()
     delete localStorage.experimental;
 }
 
 // Upgrade options before we do anything else.
 setDefaultOptions(); 
 
 /**
  * Checks whether a page is whitelisted.
- * @param url {String}
+ * @param {String} url
+ * @param {String} [type] content type to be checked, default is "DOCUMENT"
  * @return {Filter} filter that matched the URL or null if not whitelisted
  */
 function isWhitelisted(url, type)
 {
   // Ignore fragment identifier
   var index = url.indexOf("#");
   if (index >= 0)
     url = url.substring(0, index);
@@ -358,17 +359,17 @@ chrome.extension.onRequest.addListener(f
       var selectors = null;
 
       // HACK: We don't know which frame sent us the message, try to find it
       // in webRequest's frame data.
       var tabId = -1;
       var frameId = -1;
       if (sender.tab)
       {
-        var tabId = sender.tab.id;
+        tabId = sender.tab.id;
         if (tabId in frames)
         {
           for (var f in frames[tabId])
           {
             if (getFrameUrl(tabId, f) == request.frameUrl)
             {
               frameId = f;
               break;