Revert of [V8] Added Script::is_opaque flag for embedders (patchset #5 id:80001 of...

Revert of [V8] Added Script::is_opaque flag for embedders (patchset #5 id:80001 of https://codereview.chromium.org/1140673002/)

Reason for revert:
[Sheriff] Breaks chromium win compilation:
http://build.chromium.org/p/client.v8.fyi/builders/V8-Blink%20Win/builds/96

Original issue's description:
> [V8] Added Script::is_opaque flag for embedders
>
> When the page is controlled by a ServiceWorker, the ServiceWorker can return an opaque (non-CORS cross origin) resource response.
> We need to treat the messages from such script resource as opaque.
>
> Committed: https://crrev.com/7a599c5e1242d3c5ab7515ee149623da90ae69ec
> Cr-Commit-Position: refs/heads/master@{#28445}

TBR=mkwst@chromium.org,jochen@chromium.org,yangguo@chromium.org,horo@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/1135343005

Cr-Commit-Position: refs/heads/master@{#28449}