ServiceWorker

a402c930 - Fix: race-network-and-fetch-handler now uses actual |raceResponse| (#1777)

Fix: race-network-and-fetch-handler now uses actual |raceResponse| (#1777) This commit originates from the work proposed by @monica-ch and accepted a code change suggested by @domenic, but has been extensively reworked based on review feedback. This commit corrects response handling for race-network-and-fetch-handler. Primary Fix: The handler now correctly uses the actual fetch response for |raceResponse| instead of a generic [=network error=]. Minor Improvement: |timingInfo| is now included in the [=network error=], when returned by [=Create Fetch Event and Dispatch=], which simplifies the calling code.