old_contents: {
    'targets': [
      {
        'target_name': 'shortduid',
        'product_name': 'shortduid',
        'sources': [
          'src/main.cpp',
          'src/shortduid.cpp',
          'hashids/hashids.cpp',
        ],
        'cflags': [
          '-std=c++11',
          '-Ofast'
        ],
        'conditions': [
          [ 'OS=="mac"', {
            "xcode_settings": {
              'OTHER_CPLUSPLUSFLAGS' : ['-std=c++11','-stdlib=libc++','-Ofast'],
              'OTHER_LDFLAGS': ['-stdlib=libc++'],
              'MACOSX_DEPLOYMENT_TARGET': '10.9'
            }
          }],
        ],
      },
    ],
  }
  
new_contents: {
    'targets': [
      {
        'target_name': 'shortduid',
        'product_name': 'shortduid',
        'sources': [
          'src/main.cpp',
          'src/shortduid.cpp',
          'hashids/hashids.cpp',
        ],
        'cflags': [
          '-std=c++11'
        ],
        'conditions': [
          [ 'OS=="mac"', {
            "xcode_settings": {
              'OTHER_CPLUSPLUSFLAGS' : ['-std=c++11','-stdlib=libc++'],
              'OTHER_LDFLAGS': ['-stdlib=libc++'],
              'MACOSX_DEPLOYMENT_TARGET': '10.9'
            }
          }],
        ],
      },
    ],
  }
  
subject: Remove -Ofast compiling flag