Reland of NaCl cleanup: Split out irt_interfaces.cc from irt_ppapi.cc

ppapi/ppapi_proxy.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': {
       'ppapi_proxy_target': 0,
     },
     'target_conditions': [
@@ skipping 235 matching lines @@
         ],
         'defines': [
           'PPAPI_PROXY_IMPLEMENTATION',
         ],
         'include_dirs': [
           '..',
         ],
         'target_conditions': [
           ['>(nacl_untrusted_build)==1', {
             'sources': [
+              'nacl_irt/irt_interfaces.cc',
+              'nacl_irt/irt_interfaces.h',
               'nacl_irt/irt_ppapi.cc',
               'nacl_irt/irt_ppapi.h',
               'nacl_irt/irt_start.cc',
               'nacl_irt/manifest_service.cc',
               'nacl_irt/manifest_service.h',
               'nacl_irt/plugin_main.cc',
               'nacl_irt/plugin_main.h',
               'nacl_irt/plugin_startup.cc',
               'nacl_irt/plugin_startup.h',
               'nacl_irt/ppapi_dispatcher.cc',
@@ skipping 29 matching lines @@
               'proxy/ppp_video_decoder_proxy.cc',
               'proxy/serialized_flash_menu.cc',
               'proxy/video_capture_resource.cc',
             ],
           }],
         ],
       }],
     ],
   },
 }