Add the JS data pipe client to be used to implement serial send.

extensions/extensions.gyp

 # 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.
 
 {
   'variables': {
     'chromium_code': 1,
   },
   'targets': [
     {
@@ skipping 874 matching lines @@
         'browser/verified_contents_unittest.cc',
         'common/api/sockets/sockets_manifest_permission_unittest.cc',
         'common/csp_validator_unittest.cc',
         'common/event_filter_unittest.cc',
         'common/id_util_unittest.cc',
         'common/one_shot_event_unittest.cc',
         'common/permissions/manifest_permission_set_unittest.cc',
         'common/user_script_unittest.cc',
         'renderer/activity_log_converter_strategy_unittest.cc',
         'renderer/api/serial/data_receiver_unittest.cc',
+        'renderer/api/serial/data_sender_unittest.cc',
         'renderer/api/serial/serial_api_unittest.cc',
         'renderer/api_test_base.cc',
         'renderer/api_test_base.h',
         'renderer/api_test_base_unittest.cc',
         'renderer/event_unittest.cc',
         'renderer/json_schema_unittest.cc',
         'renderer/messaging_utils_unittest.cc',
         'renderer/module_system_test.cc',
         'renderer/module_system_test.h',
         'renderer/module_system_unittest.cc',
@@ skipping 28 matching lines @@
           'browser/api/cast_channel/logging.proto'
       ],
       'variables': {
           'proto_in_dir': 'browser/api/cast_channel',
           'proto_out_dir': 'extensions/browser/api/cast_channel',
       },
       'includes': [ '../build/protoc.gypi' ]
     },
   ]
 }