Issue 4580 - Replace ext.devtools with devtools

background.js

Index: background.js
===================================================================
--- a/background.js
+++ b/background.js
@@ -74,20 +74,18 @@
     filterError: false,
     downloadStatus: "synchronize_ok",
     showNotificationUI: false,
     showPageOptions: false
   };
   updateFromURL(params);
 
   let modules = {};
-  window.require = function(module)
-  {
-    return modules[module];
-  };
+
+  const require = window.require = module => modules[module];
 
   modules.utils = {
     Utils: {
       getDocLink(link)
       {
         return "https://adblockplus.org/redirect?link=" + encodeURIComponent(link);
       },
       get appLocale()
@@ -536,18 +534,22 @@
               whitelisted: isWhitelisted
             }
           ]
         }
       }, "*");
     }, 1000);
   }
 
-  ext.devtools.onCreated.addListener((panel) =>
+  let {port} = require("messaging");
+
+  port.on("devtools.ready", (message, sender) =>
   {
+    let panel = sender.page;
+
     // blocked request
     panel.sendMessage({
       type: "add-record",
       request: {
         url: "http://adserver.example.com/ad_banner.png",
         type: "IMAGE",
         docDomain: "example.com"
       },