Intermittent crash of /css-transforms-1_dev/html/transofrmed-rotateY-1.htm

[KiChjang]

Ran 9977 tests finished in 931.0 seconds.
  • 9976 ran as expected. 132 tests skipped.
  • 1 tests crashed unexpectedly

Tests with unexpected results:
  ▶ CRASH [expected PASS] /css-transforms-1_dev/html/transofrmed-rotateY-1.htm
  │ 
  │ Xlib:  extension "XFree86-VidModeExtension" missing on display ":0".
  │ Shutting down the Constellation after generating an output file or exit flag specified
  │ Xlib:  extension "XFree86-VidModeExtension" missing on display ":0".
  │ Shutting down the Constellation after generating an output file or exit flag specified
  │ ERROR:servo: called `Result::unwrap()` on an `Err` value: RecvError
  └ thread panicked while processing panic. aborting.

[jdm]

Same symptoms as #12553 so merging with that one.