v8binding: Do not hold a cross origin ScriptState in IDL callback function

Make IDL callback function not hold a ScriptState of its
creation context when it's cross origin from the incumbent

Not holding a cross origin ScriptState, there is much
less risk to access a cross origin context.

IDL callback interface will follow the same approach in
a separate patch.

Bug: 892755, 886588, 904218
Change-Id: Ie55b436fcc5f66f4ee053ef08ad98ea68fb3a2d6
Reviewed-on: https://chromium-review.googlesource.com/c/1314023
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Hitoshi Yoshida <peria@chromium.org>
Commit-Queue: Yuki Shiino <yukishiino@chromium.org>
Cr-Commit-Position: refs/heads/master@{#609662}
28 files changed