[mojo-edk] Add explicit message object APIs

mojo/mojo_edk.gyp

 # Copyright 2015 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.
 
 {
   'includes': [
     'mojo_variables.gypi',
   ],
   'target_defaults' : {
     'include_dirs': [
@@ skipping 66 matching lines @@
         'edk/system/data_pipe_control_message.h',
         'edk/system/data_pipe_producer_dispatcher.cc',
         'edk/system/data_pipe_producer_dispatcher.h',
         'edk/system/dispatcher.cc',
         'edk/system/dispatcher.h',
         'edk/system/handle_signals_state.h',
         'edk/system/handle_table.cc',
         'edk/system/handle_table.h',
         'edk/system/mapping_table.cc',
         'edk/system/mapping_table.h',
+        'edk/system/message_for_transit.cc',
+        'edk/system/message_for_transit.h',
         'edk/system/message_pipe_dispatcher.cc',
         'edk/system/message_pipe_dispatcher.h',
         'edk/system/node_channel.cc',
         'edk/system/node_channel.h',
         'edk/system/node_controller.cc',
         'edk/system/node_controller.h',
         'edk/system/options_validation.h',
         'edk/system/platform_handle_dispatcher.cc',
         'edk/system/platform_handle_dispatcher.h',
         'edk/system/ports/event.cc',
@@ skipping 161 matching lines @@
         'mojo_public.gyp:mojo_public_test_support',
         'mojo_system_impl',
         'mojo_test_support_impl',
       ],
       'sources': [
         'edk/test/run_all_perftests.cc',
       ],
     },
   ],
 }