Replace JSON (de)serialization of extension messages with direct Value pickling.

chrome/test/data/devtools/extensions/devtools_messaging/devtools.js

 // Copyright (c) 2013 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.
 
 function output(msg) {
   chrome.devtools.inspectedWindow.eval("console.log(unescape('" +
       escape(msg) + "'));")
 }
 
 var hadErrors = false;
@@ skipping 12 matching lines @@
 }
 
 function step1() {
   chrome.extension.sendRequest("foo", function(response) {
     assertEquals('onRequest callback: "foo"', response);
     step2();
   });
 }
 
 function step2() {
-  var object = { "string": "foo", "number": 42 };
+  var object = [{"string": "foo"}, {"number": 42}];
   chrome.extension.sendRequest(object, function(response) {
     assertEquals('onRequest callback: ' + JSON.stringify(object), response);
     step3();
   });
 }
 
 function step3() {
   function onMessage(message) {
     assertEquals("port.onMessage: foo", message);
     completeTest();
   }
   var port = chrome.runtime.connect();
   port.onMessage.addListener(onMessage);
   port.postMessage("foo");
 }
 
 step1();