Revert of Skip the Service Worker CORS fallback for same origin requests. [2/2 chromi...

Revert of Skip the Service Worker CORS fallback for same origin requests. [2/2 chromium] (patchset #1 id:40001 of https://codereview.chromium.org/1242953007/)

Reason for revert:
This broke http/tests/serviceworker/fetch-request-fallback.html, causing failures on 3 bots and timeouts on 18 bots.

See http://test-results.appspot.com/dashboards/flakiness_dashboard.html#tests=http%2Ftests%2Fserviceworker%2Ffetch-request-fallback.html&testType=layout-tests

Original issue's description:
> Skip the Service Worker CORS fallback for same origin requests. [2/2 chromium]
>
> We are sending CORS fallback response from the browser process to the page's renderer process, when the ServiceWorker doesn't handle the CORS fetch request.
> But when the request URL's origin is same as the page's security origin, we can skip the fallback and send the request from the browser process.
>
> This change will improve the delay of the CORS fallback for same origin requests, especially when the renderer main thread is busy.
>
blink: https://codereview.chromium.org/1243353002/
> 2/2 chromium: this cl.
>
> BUG=512764
>
> Committed: https://crrev.com/97b13409b0c601f21f048744fa8e31852b476337
> Cr-Commit-Position: refs/heads/master@{#341482}

TBR=falken@chromium.org,tyoshino@chromium.org,horo@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=512764

Review URL: https://codereview.chromium.org/1258893004

Cr-Commit-Position: refs/heads/master@{#341499}