chromium/third_party/blink/web_tests/external/wpt/layout-instability/idlharness-expected.txt

This is a testharness.js-based test.
[FAIL] LayoutShift interface: default toJSON operation on layoutShift
  assert_true: property "id" should be present in the output of LayoutShift.prototype.toJSON() expected true got false
Harness: the test ran to completion.