Separate out the platform-independent parts of Channel reading.

ipc/ipc.gypi

 # Copyright (c) 2011 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.
 
 {
   'target_defaults': {
     'variables': {
       'ipc_target': 0,
     },
     'target_conditions': [
       # This part is shared between the targets defined below.
       ['ipc_target==1', {
         'sources': [
           'file_descriptor_set_posix.cc',
           'file_descriptor_set_posix.h',
           'ipc_channel.h',
           'ipc_channel_handle.h',
           'ipc_channel_posix.cc',
           'ipc_channel_posix.h',
           'ipc_channel_proxy.cc',
           'ipc_channel_proxy.h',
+          'ipc_channel_reader.cc',
+          'ipc_channel_reader.h',
           'ipc_channel_win.cc',
           'ipc_channel_win.h',
           'ipc_descriptors.h',
           'ipc_export.h',
           'ipc_logging.cc',
           'ipc_logging.h',
           'ipc_message.cc',
           'ipc_message.h',
           'ipc_message_macros.h',
           'ipc_message_utils.cc',
@@ skipping 68 matching lines @@
           'configurations': {
             'Common_Base': {
               'msvs_target_platform': 'x64',
             },
           },
         },
       ],
     }],
   ],
 }