old_contents: {
    'targets': [
      {
        'target_name': 'ffi_bindings',
        'sources': [
            'src/ffi.cc'
          , 'src/callback_info.cc'
          , 'src/pointer.cc'
          , 'src/threaded_callback_invokation.cc'
          , 'src/foreign_caller.cc'
        ],
        'include_dirs': [
            'deps/libffi/include'
        ],
        'conditions': [
          ['OS=="win"', {
            'libraries': [
                'deps/libffi/.libs/libffi.lib'
            ],
            'dependencies': [
                'deps/dlfcn-win32/dlfcn.gyp:dlfcn'
              , 'deps/pthreads-win32/pthread.gyp:pthread'
            ]
          }, {
            'libraries': [
                'deps/libffi/.libs/libffi.a'
            ],
          }],
          ['OS=="mac"', {
            'xcode_settings': {
              'MACOSX_DEPLOYMENT_TARGET': '10.5',
              'OTHER_CFLAGS': [
                  '-ObjC++'
              ]
            },
            'libraries': [
                '-lobjc'
            ],
          }]
        ]
      }
    ]
  }
  
new_contents: {
    'targets': [
      {
        'target_name': 'ffi_bindings',
        'sources': [
            'src/ffi.cc'
          , 'src/callback_info.cc'
          , 'src/pointer.cc'
          , 'src/threaded_callback_invokation.cc'
          , 'src/foreign_caller.cc'
        ],
        'include_dirs': [
            'deps/libffi/include'
        ],
        'conditions': [
          ['OS=="win"', {
            'libraries': [
                '../deps/libffi/.libs/libffi.lib'
            ],
            'dependencies': [
                'deps/dlfcn-win32/dlfcn.gyp:dlfcn'
              , 'deps/pthreads-win32/pthread.gyp:pthread'
            ]
          }, {
            'libraries': [
                '../deps/libffi/.libs/libffi.a'
            ],
          }],
          ['OS=="mac"', {
            'xcode_settings': {
              'MACOSX_DEPLOYMENT_TARGET': '10.5',
              'OTHER_CFLAGS': [
                  '-ObjC++'
              ]
            },
            'libraries': [
                '-lobjc'
            ],
          }]
        ]
      }
    ]
  }
  
subject: Update the bindings.gyp file to select the proper libffi lib file.