polymer/wct.conf.json

{
  "suites": ["test/runner.html"],
  "environmentImports": [
    "test-fixture/test-fixture.html"
  ],
  "plugins": {
    "local": {
      "browserOptions": {
        "chrome": [
          "headless",
          "disable-gpu",
          "no-sandbox"
        ]
      }
    }
  }
}