Add minidump_extensions.h

compat/compat.gyp

 # Copyright 2014 The Crashpad Authors. All rights reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
 #     http://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
@@ skipping 14 matching lines @@
         'include_dirs': [
           'mac',
           'non_win',
         ],
       },
       'sources': [
         'mac/AvailabilityMacros.h',
         'mac/mach/mach.h',
         'mac/mach-o/loader.h',
         'mac/servers/bootstrap.h',
+        'non_mac/mach/mach.h',
         'non_win/dbghelp.h',
         'non_win/minwinbase.h',
         'non_win/timezoneapi.h',
         'non_win/verrsrc.h',
         'non_win/winnt.h',
       ],
     },
   ],
 }