Issue 3251 - Simplify messaging from child scripts to parent

lib/child/contentPolicy.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 298 matching lines @@
     Utils.runAsync(postProcessNodes);
   }
 }
 
 /**
  * Processes nodes scheduled for post-processing (typically hides them).
  */
 function postProcessNodes()
 {
   if (!collapsedClass)
-  {
-    let response = sendSyncMessage("AdblockPlus:GetCollapsedClass");
-    if (response.length)
-      collapsedClass = response[0];
-
-    if (!collapsedClass)
-    {
-      Utils.runAsync(postProcessNodes);
-      return;
-    }
-  }
+    collapsedClass = sendSyncMessage("AdblockPlus:GetCollapsedClass");
 
   let nodes = scheduledNodes;
   scheduledNodes = null;
+
+  if (!collapsedClass)
+    return;
 
   for (let node of nodes)
   {
     // adjust frameset's cols/rows for frames
     let parentNode = node.parentNode;
     if (parentNode && parentNode instanceof Ci.nsIDOMHTMLFrameSetElement)
     {
       let hasCols = (parentNode.cols && parentNode.cols.indexOf(",") > 0);
       let hasRows = (parentNode.rows && parentNode.rows.indexOf(",") > 0);
       if ((hasCols || hasRows) && !(hasCols && hasRows))
       {
         let index = -1;
         for (let frame = node; frame; frame = frame.previousSibling)
           if (frame instanceof Ci.nsIDOMHTMLFrameElement || frame instanceof Ci.nsIDOMHTMLFrameSetElement)
             index++;
 
         let property = (hasCols ? "cols" : "rows");
         let weights = parentNode[property].split(",");
         weights[index] = "0";
         parentNode[property] = weights.join(",");
       }
     }
     else
       node.classList.add(collapsedClass);
   }
 }