Add support for internal overrides for Mac

remoting/remoting_host.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.
 
 {
   'includes': [
     'remoting_host_linux.gypi',
     'remoting_host_mac.gypi',
     'remoting_host_win.gypi',
   ],
@@ skipping 115 matching lines @@
                   'dependencies' : [
                     '../ui/ozone/ozone.gyp:ozone',
                   ]
                 }],
               ],
             }],
             ['OS=="mac"', {
               'dependencies': [
                 '../third_party/google_toolbox_for_mac/google_toolbox_for_mac.gyp:google_toolbox_for_mac',
               ],
+              'variables': {
+                # Include internal_mac-inl.h only if it exists.
+                'use_remoting_macosx_internal%':
+                  '<!(python -c "import os; print 1 if os.path.exists(\'tools/internal/internal_mac-inl.h\') else 0")'
+              },
+              'conditions': [
+                ['use_remoting_macosx_internal==1', {
+                  'sources': [
+                    'internal/internal_mac-inl.h'
+                  ],
+                  'defines': [
+                    'USE_REMOTING_MACOSX_INTERNAL'
+                  ]
+                }]
+              ],
               'link_settings': {
                 'libraries': [
                   '$(SDKROOT)/System/Library/Frameworks/OpenGL.framework',
                   'libpam.a',
                ],
               },
             }],
             ['OS=="win"', {
               'defines': [
                 '_ATL_NO_EXCEPTIONS',
@@ skipping 576 matching lines @@
                 }],  # mac_breakpad==1
               ],  # conditions
             }],  # OS=mac
           ],
         },  # end of target 'remoting_it2me_native_messaging_host'
       ],  # end of 'targets'
     }],  # # end of OS!="win" and enable_it2me_host==1
 
   ],  # end of 'conditions'
 }