Require manifests for native messaging hosts.

chrome/test/data/native_messaging/native_hosts/echo.py

-#!/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 client in python.
-# All this client does is echo the text it receives back at the extension.
-
-import sys
-import struct
-
-def Main():
-  message_number = 0
-
-  while 1:
-    # Read the message type (first 4 bytes).
-    text_length_bytes = sys.stdin.read(4)
-
-    if len(text_length_bytes) == 0:
-      break
-
-    # Read the message length (4 bytes).
-    text_length = struct.unpack('i', text_length_bytes)[0]
-
-    # Read the text (JSON object) of the message.
-    text = sys.stdin.read(text_length).decode('utf-8')
-
-    message_number += 1
-
-    response = '{{"id": {0}, "echo": {1}}}'.format(message_number,
-                                                   text).encode('utf-8')
-
-    try:
-      sys.stdout.write(struct.pack("I", len(response)))
-      sys.stdout.write(response)
-      sys.stdout.flush()
-    except IOError:
-      break
-
-if __name__ == '__main__':
-  Main()