Use FrameTreeNode ID as frameId in extension APIs

chrome/test/data/extensions/api_test/messaging/connect_crash/test.js

 // Copyright 2015 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.
 
 chrome.runtime.onConnect.addListener(function(port) {
+  var is_ready_to_crash = false;
   var succeed1 = chrome.test.callbackAdded();
   var succeed2 = chrome.test.callbackAdded();
-  var succeed3 = chrome.test.callbackAdded();
 
   port.onMessage.addListener(function(msg) {
-    chrome.test.log('port.onMessage was triggered.');
-    chrome.test.assertEq('Hello from content script', msg);
+    chrome.test.assertEq('is_ready_to_crash', msg);
+    is_ready_to_crash = true;
+    chrome.test.sendMessage('ready_to_crash');
+    // Now the browser test should kill the tab, and the port should be closed.
+  });
+  port.onDisconnect.addListener(function() {
+    chrome.test.log('port.onDisconnect was triggered.');
+    chrome.test.assertTrue(is_ready_to_crash);
     succeed1();
   });
 
-  port.onDisconnect.addListener(function() {
-    chrome.test.log('port.onDisconnect was triggered.');
+  chrome.tabs.sendMessage(port.sender.tab.id, 'Rob says hi', function() {
+    chrome.test.log('tab.sendMessage\'s response callback was invoked');
+    chrome.test.assertNoLastError();
     succeed2();
   });
-
-  chrome.tabs.sendMessage(port.sender.tab.id, 'msg from tab', function(reply) {
-    chrome.test.log('tab.sendMessage\'s response callback was invoked');
-    chrome.test.assertEq('Reply here', reply);
-    succeed3();
-  });
 });
-
-chrome.test.getConfig(function(config) {
-  var url = 'http://localhost:' + config.testServer.port +
-      '/extensions/test_file.html?will_test_connect_and_sendMessage';
-  // Content script will try to connect and trigger onConnect.
-  chrome.tabs.create({
-    url: url
-  });
-});