Revert of [ServivceWorker] Treat rejecting respondWith as a Network Error (patchset #4 id:60001 of https://codereview.chromium.org/571843003/)

Reason for revert:
WebServiceWorkerResponse's status is not initialised.
This may cause problems.

I will re-land this patch after https://codereview.chromium.org/575153002/ is submitted.

Original issue's description:
> [ServivceWorker] Treat rejecting respondWith as a Network Error
> 
> Chromium side change is this: https://codereview.chromium.org/574643003/
> 
> 
> BUG=411173
> TEST=layouttest http/tests/serviceworker/
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=182147

TBR=yhirano@chromium.org,mkwst@chromium.org,tkent@chromium.org,nhiroki@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=411173

Review URL: https://codereview.chromium.org/580993002

git-svn-id: svn://svn.chromium.org/blink/trunk@182204 bbb929c8-8fbe-4397-9dbb-9b2b20218538