Update references to the extension messaging APIs to point to the "runtime"

chrome/test/data/extensions/api_test/executescript/in_frame/test.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.
 
 var pass = chrome.test.callbackPass;
 var fail = chrome.test.callbackFail;
 var assertEq = chrome.test.assertEq;
 var assertTrue = chrome.test.assertTrue;
 var relativePath =
     '/files/extensions/api_test/executescript/in_frame/test_executescript.html';
 var testUrl = 'http://a.com:PORT' + relativePath;
 
 chrome.tabs.onUpdated.addListener(function(tabId, changeInfo, tab) {
   if (changeInfo.status != 'complete')
     return;
 
   chrome.test.runTests([
     function executeJavaScriptCodeInAllFramesShouldSucceed() {
       var script_file = {};
-      script_file.code = "var extensionPort = chrome.extension.connect();";
+      script_file.code = "var extensionPort = chrome.runtime.connect();";
       script_file.code = script_file.code +
           "extensionPort.postMessage({message: document.title});";
       script_file.allFrames = true;
       var counter = 0;
       var totalTitles = '';
       function eventListener(port) {
         port.onMessage.addListener(function(data) {
           counter++;
           totalTitles += data.message;
         });
       };
-      chrome.extension.onConnect.addListener(eventListener);
+      chrome.runtime.onConnect.addListener(eventListener);
       chrome.tabs.executeScript(tabId, script_file, pass(function() {
         assertEq(counter, 5);
         assertEq(totalTitles, 'frametest0test1test2test3');
-        chrome.extension.onConnect.removeListener(eventListener);
+        chrome.runtime.onConnect.removeListener(eventListener);
       }));
     },
 
     function insertCSSTextInAllFramesShouldSucceed() {
       var css_file = {};
       css_file.code = "p {display:none;}";
       css_file.allFrames = true;
       var newStyle = '';
       var counter = 0;
       function eventListener(port) {
         port.onMessage.addListener(function(data) {
           counter++;
           newStyle += data.message;
         });
       };
-      chrome.extension.onConnect.addListener(eventListener);
+      chrome.runtime.onConnect.addListener(eventListener);
       chrome.tabs.insertCSS(tabId, css_file, function() {
         var script_file = {};
         script_file.file = 'script.js';
         script_file.allFrames = true;
         chrome.tabs.executeScript(tabId, script_file,
           pass(function() {
             assertEq(newStyle, 'nonenonenonenone');
             assertEq(counter, 4);
-            chrome.extension.onConnect.removeListener(eventListener);
+            chrome.runtime.onConnect.removeListener(eventListener);
         }));
       });
     }
   ]);
 });
 
 chrome.test.getConfig(function(config) {
   testUrl = testUrl.replace(/PORT/, config.testServer.port);
   chrome.tabs.create({ url: testUrl });
 });