Issue 2084 - Detect our content script instead checking for anonymous frames

include.preload.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2015 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 61 matching lines @@
   }
 }
 
 function checkSitekey()
 {
   var attr = document.documentElement.getAttribute("data-adblockkey");
   if (attr)
     ext.backgroundPage.sendMessage({type: "add-sitekey", token: attr});
 }
 
-function isInlineFrame(element)
+function isFrameWithoutContentScript(element)
 {
   var contentDocument;
   try
   {
     contentDocument = element.contentDocument;
   }
   catch (e)
   {
-    return false;  // third-party
+    // This is a third-party frame. Hence we can't access it.
+    // But that's fine, our content script should already run there.
+    return false;
   }
 
+  // The element isn't a <frame>, <iframe> or <object> with "data" attribute.
   if (!contentDocument)
-    return false;  // not a frame
+    return false;
 
-  return contentDocument.location.protocol == "about:";
+  // Return true, if the element is a first-party frame which doesn't
+  // have this function, hence our content script isn't running there.
+  // Those are dynamically created frames as well as frames
+  // with "about:blank", "about:srcdoc" and "javascript:" URL.
+  return !("isFrameWithoutContentScript" in contentDocument.defaultView);
 }
 
 function reinjectRulesWhenRemoved(document, style)
 {
   var MutationObserver = window.MutationObserver || window.WebKitMutationObserver;
   if (!MutationObserver)
     return;
 
   var observer = new MutationObserver(function(mutations)
   {
@@ skipping 141 matching lines @@
   {
     var element = event.target;
 
     if (/^i?frame$/.test(element.localName))
       checkCollapse(element);
 
     // prior to Chrome 37, content scripts cannot run on about:blank,
     // about:srcdoc and javascript: URLs. Moreover, as of Chrome 40
     // "load" and "error" events aren't dispatched there. So we have
     // to apply element hiding and collapsing from the parent frame.
-    if (/\bChrome\//.test(navigator.userAgent) && isInlineFrame(element))
+    if (/\bChrome\//.test(navigator.userAgent) && isFrameWithoutContentScript(element))
     {
       init(element.contentDocument);
 
       for (var tagName in typeMap)
         Array.prototype.forEach.call(element.contentDocument.getElementsByTagName(tagName), checkCollapse);
     }
   }, true);
 
   ext.backgroundPage.sendMessage({type: "get-selectors"}, setElemhideCSSRules);
 }
 
 if (document instanceof HTMLDocument)
 {
   checkSitekey();
   init(document);
 }