Improve native messaging documentation

chrome/common/extensions/docs/examples/api/nativeMessaging/host/native-messaging-example-host

 #!/usr/bin/env python
 # 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.
 
 # A simple native messaging host. Shows a Tkinter dialog with incoming messages
 # that also allows to send message back to the webapp.
 
 import struct
 import sys
 import threading
 import Queue
 
 try:
   import Tkinter
   import tkMessageBox
 except ImportError:
   Tkinter = None
 
+# On Windows, the default I/O mode is O_TEXT. Set this to O_BINARY
+# to avoid unwanted modifications of the input/output streams.
+if sys.platform == "win32":
+  import os, msvcrt
+  msvcrt.setmode(sys.stdin.fileno(), os.O_BINARY)
+  msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY)
+
 # Helper function that sends a message to the webapp.
 def send_message(message):
    # Write message size.
   sys.stdout.write(struct.pack('I', len(message)))
   # Write the message itself.
   sys.stdout.write(message)
   sys.stdout.flush()
 
 # Thread that reads messages from the webapp.
 def read_thread_func(queue):
@@ skipping 82 matching lines @@
   thread.daemon = True
   thread.start()
 
   main_window.mainloop()
 
   sys.exit(0)
 
 
 if __name__ == '__main__':
   Main()