[NaCl SDK] Make the SDK examples buildable as a packaged app.

native_client_sdk/src/examples/websocket/example.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.
 
 // Called by the common.js module.
 function attachListeners() {
   document.getElementById('connectForm').addEventListener('submit', doConnect);
   document.getElementById('sendForm').addEventListener('submit', doSend);
   document.getElementById('closeButton').addEventListener('click', doClose);
 }
@@ skipping 16 matching lines @@
   // Send a request message. See also websocket.cc for the request format.
   var message = document.getElementById('message').value;
   common.naclModule.postMessage('s;' + message);
   event.preventDefault();
 }
 
 function doClose() {
   // Send a request message. See also websocket.cc for the request format.
   common.naclModule.postMessage('c;');
 }
+
+function handleMessage(message) {
+  common.logMessage(message.data + '\n');
+}