node/test/addons/openssl-binding/binding.gyp

{
  'targets': [
    {
      'target_name': 'binding',
      'conditions': [
         ['node_use_openssl=="true"', {
           'sources': ['binding.cc'],
           'include_dirs': ['../../../deps/openssl/openssl/include'],
         }]
      ]
    },
  ]
}