Use FrameTreeNode ID as frameId in extension APIs

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

+// Copyright (c) 2015 The Chromium Authors. All rights reserved.

[Devlin, 2015/11/13 21:16:27]

nit: no (c) (everywhere)

[robwu, 2015/12/07 23:44:22]

Done.

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+var port = chrome.runtime.connect();
+port.onDisconnect.addListener(function() {
+  chrome.test.fail('onDisconnect should not be triggered because the ' +
+     'background page exists and the tab should have been crashed');
+});
+
+var ref;
+chrome.runtime.onMessage.addListener(function(msg, sender, sendResponse) {
+  chrome.test.assertEq('Rob says hi', msg);
+  port.postMessage('is_ready_to_crash');
+  // Keep the callback around to avoid test flakiness due to GC.
+  ref = sendResponse;
+
+  // TODO(robwu): Remove the following line once crbug.com/439780 is fixed.
+  // (the response callback is not automatically invoked when the tab crashes).
+  sendResponse();
+
+  // Keep the port open - do not send a response.
+  return true;
+});