drupal_routes/sites/all/themes/bootstrap/grunt/config/autoprefixer.js

module.exports = function (grunt, options) {
  return {
    options: {
      browsers: [
        "Android 2.3",
        "Android >= 4",
        "Chrome >= 20",
        "Firefox >= 24",
        "Explorer >= 8",
        "iOS >= 6",
        "Opera >= 12",
        "Safari >= 6"
      ],
      map: true
    },
    css: {
      src: ['css/**/*.css']
    },
    dev: {
      src: ['css/<%= latestVersion %>/overrides.css']
    }
  }
};