Issue 4580 - Replace ext.devtools with devtools

ext/content.js

Index: ext/content.js
===================================================================
--- a/ext/content.js
+++ b/ext/content.js
@@ -44,40 +44,40 @@
         for (let message of queue)
           backgroundFrame.contentWindow.postMessage(message, "*");
       }
       window.removeEventListener("message", loadHandler);
     }
   };
   window.addEventListener("message", loadHandler);
 
-  ext.backgroundPage = {
-    _sendRawMessage(message)
-    {
-      if (messageQueue)
-        messageQueue.push(message);
-      else
-        backgroundFrame.contentWindow.postMessage(message, "*");
-    }
-  };
-
   /* Polyfills */
 
   if (!("runtime" in chrome))
     chrome.runtime = {};
 
+  function sendRawMessage(message)
+  {
+    if (messageQueue)
+      messageQueue.push(message);
+    else
+      backgroundFrame.contentWindow.postMessage(message, "*");
+  }
+
+  chrome.runtime.connect = () =>
+  {
+    sendRawMessage({type: "connect"});
+    return {onMessage: ext.onMessage};
+  };
+
   chrome.runtime.sendMessage = (message, responseCallback) =>
   {
     let messageId = ++maxMessageId;
 
-    ext.backgroundPage._sendRawMessage({
-      type: "message",
-      messageId,
-      payload: message
-    });
+    sendRawMessage({type: "message", messageId, payload: message});
 
     if (responseCallback)
     {
       let callbackWrapper = event =>
       {
         if (event.data.type == "response" && event.data.messageId == messageId)
         {
           window.removeEventListener("message", callbackWrapper);