Refactored the abstraction layer to address prerendered pages on Safari caused by leaky abstraction

webrequest.js

 /*
  * This file is part of Adblock Plus <http://adblockplus.org/>,
  * Copyright (C) 2006-2013 Eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 28 matching lines @@
 {
   if (action in importantNotifications)
   {
     // Execute delayed to prevent multiple executions in a quick succession
     if (onFilterChangeTimeout != null)
       window.clearTimeout(onFilterChangeTimeout);
     onFilterChangeTimeout = window.setTimeout(onFilterChange, 2000);
   }
 });
 
-function onBeforeRequest(url, type, tab, frame)
+function onBeforeRequest(url, type, page, frame)
 {
-  if (isFrameWhitelisted(tab, frame))
+  if (isFrameWhitelisted(page, frame))
     return true;
 
   var docDomain = extractHostFromURL(frame.url);
   var filter = defaultMatcher.matchesAny(
     url,
     type == "sub_frame" ? "SUBDOCUMENT" : type.toUpperCase(),
     docDomain,
     isThirdParty(extractHostFromURL(url), docDomain)
   );
 
-  FilterNotifier.triggerListeners("filter.hitCount", filter, 0, 0, tab);
+  FilterNotifier.triggerListeners("filter.hitCount", filter, 0, 0, page);
   return !(filter instanceof BlockingFilter);
 }
 
 ext.webRequest.onBeforeRequest.addListener(onBeforeRequest);
 
 if (require("info").platform == "chromium")
 {
   function onHeadersReceived(details)
   {
     if (details.tabId == -1)
       return;
 
     if (details.type != "main_frame" && details.type != "sub_frame")
       return;
 
-    var tab = new Tab({id: details.tabId});
-    var frame = new Frame({id: details.frameId, tab: tab});
+    var page = new ext.Page({id: details.tabId});
+    var frame = new ext.Frame({frameId: details.frameId, tabId: details.tabId});
 
     if (frame.url != details.url)
       return;
 
     for (var i = 0; i < details.responseHeaders.length; i++)
     {
       var header = details.responseHeaders[i];
       if (header.name.toLowerCase() == "x-adblock-key" && header.value)
-        processKeyException(header.value, tab, frame);
+        processKeyException(header.value, page, frame);
     }
   }
 
   chrome.webRequest.onHeadersReceived.addListener(onHeadersReceived, {urls: ["<all_urls>"]}, ["responseHeaders"]);
 }