Make the externally connectable browser test clobber all of the builtins,

chrome/renderer/resources/extensions/miscellaneous_bindings.js

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This contains unprivileged javascript APIs for extensions and apps.  It
 // can be loaded by any extension-related context, such as content scripts or
 // background pages. See user_script_slave.cc for script that is loaded by
 // content scripts only.
 
   // TODO(kalman): factor requiring chrome out of here.
@@ skipping 80 matching lines @@
 
   // Helper function for dispatchOnRequest.
   function handleSendRequestError(isSendMessage,
                                   responseCallbackPreserved,
                                   sourceExtensionId,
                                   targetExtensionId,
                                   sourceUrl) {
     var errorMsg = [];
     var eventName = isSendMessage ? "runtime.onMessage" : "extension.onRequest";
     if (isSendMessage && !responseCallbackPreserved) {
-      errorMsg.push(
+      $Array.push(errorMsg,
           "The chrome." + eventName + " listener must return true if you " +
           "want to send a response after the listener returns");
     } else {
-      errorMsg.push(
+      $Array.push(errorMsg,
           "Cannot send a response more than once per chrome." + eventName +
           " listener per document");
     }
-    errorMsg.push("(message was sent by extension" + sourceExtensionId);
+    $Array.push(errorMsg, "(message was sent by extension" + sourceExtensionId);
     if (sourceExtensionId != "" && sourceExtensionId != targetExtensionId)
-      errorMsg.push("for extension " + targetExtensionId);
+      $Array.push(errorMsg, "for extension " + targetExtensionId);
     if (sourceUrl != "")
-      errorMsg.push("for URL " + sourceUrl);
+      $Array.push(errorMsg, "for URL " + sourceUrl);
     lastError.set(eventName, errorMsg.join(" ") + ").", null, chrome);
   }
 
   // Helper function for dispatchOnConnect
   function dispatchOnRequest(portId, channelName, sender,
                              sourceExtensionId, targetExtensionId, sourceUrl,
                              isExternal) {
     var isSendMessage = channelName == kMessageChannel;
     var requestEvent = null;
     if (isSendMessage) {
@@ skipping 181 matching lines @@
         port = null;
       }
     });
   };
 
   function sendMessageUpdateArguments(functionName) {
     // Align missing (optional) function arguments with the arguments that
     // schema validation is expecting, e.g.
     //   extension.sendRequest(req)     -> extension.sendRequest(null, req)
     //   extension.sendRequest(req, cb) -> extension.sendRequest(null, req, cb)
-    var args = Array.prototype.splice.call(arguments, 1);  // skip functionName
+    var args = $Array.splice(arguments, 1);  // skip functionName
     var lastArg = args.length - 1;
 
     // responseCallback (last argument) is optional.
     var responseCallback = null;
     if (typeof(args[lastArg]) == 'function')
       responseCallback = args[lastArg--];
 
     // request (second argument) is required.
     var request = args[lastArg--];
 
@@ skipping 13 matching lines @@
 exports.Port = Port;
 exports.createPort = createPort;
 exports.sendMessageImpl = sendMessageImpl;
 exports.sendMessageUpdateArguments = sendMessageUpdateArguments;
 
 // For C++ code to call.
 exports.hasPort = hasPort;
 exports.dispatchOnConnect = dispatchOnConnect;
 exports.dispatchOnDisconnect = dispatchOnDisconnect;
 exports.dispatchOnMessage = dispatchOnMessage;