ServiceWorker: Mark ready.html with 'Skip' instead of 'Failure Timeout'

This test always doesn't work now because we are modifying '.ready'
implementation to catch up with the latest spec, so the test should
be skipped until the fix arrives.


BUG=399533
TEST=n/a
NOTRY=true

Review URL: https://codereview.chromium.org/529623003

git-svn-id: svn://svn.chromium.org/blink/trunk@181164 bbb929c8-8fbe-4397-9dbb-9b2b20218538