Add an API test to exersize the open error case. This is a regression test for

chrome/test/data/extensions/api_test/cast_channel/api/test_open_error.js

Index: chrome/test/data/extensions/api_test/cast_channel/api/test_open_error.js
===================================================================
--- chrome/test/data/extensions/api_test/cast_channel/api/test_open_error.js	(revision 0)
+++ chrome/test/data/extensions/api_test/cast_channel/api/test_open_error.js	(revision 0)
@@ -0,0 +1,15 @@
+// Copyright 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.
+
+var onError = function(channel) {
+  chrome.test.notifyPass();
+}
+
+var onOpen = function(channel) {
+  assertClosedChannel(channel);
+  chrome.test.succeed();
+};
+
+chrome.cast.channel.onError.addListener(onError);
+chrome.cast.channel.open( 'cast://192.168.1.1:8009', onOpen);