Introduce IPC::Channel::Create*() to ensure it being heap-allocated.

ipc/ipc.gypi

 # 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.
 
 {
   '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.cc',
           'ipc_channel.h',
+          'ipc_channel_common.cc',
           'ipc_channel_factory.cc',
           'ipc_channel_factory.h',
           'ipc_channel_handle.h',
           'ipc_channel_nacl.cc',
           'ipc_channel_nacl.h',
           'ipc_channel_posix.cc',
           'ipc_channel_posix.h',
           'ipc_channel_proxy.cc',
           'ipc_channel_proxy.h',
           'ipc_channel_reader.cc',
@@ skipping 57 matching lines @@
             'sources!': [
               'ipc_channel_factory.cc',
               'unix_domain_socket_util.cc',
             ],
           }],
         ],
       }],
     ],
   },
 }