What steps will reproduce the problem?
(1) use a cookie to determine user's/browser's eligibility to participate in canarying experiment for a new worker script version
(2) serve different serviceworker script and/or importScripts script contents based on the eligibility cookie and the current versioning situation

What is the expected output?
System works

What do you see instead?
1. Cookies not sent in worker script fetches
2. importScripts results do not matter for update check

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