Revert of Call directly to c callbacks in Invoke instead of transitioning to js and back out. (patchset #9 id:150001 of https://codereview.chromium.org/864273002/)

Reason for revert:
threading4 flakiness

Original issue's description:
> Call directly to c callbacks in Invoke instead of transitioning to js and back out.
>
> BUG=
>
> Committed: https://crrev.com/ce457e2b596c3ccf5bf454eeed0969f3f3efd174
> Cr-Commit-Position: refs/heads/master@{#26231}

TBR=verwaest@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=

Review URL: https://codereview.chromium.org/873583003

Cr-Commit-Position: refs/heads/master@{#26236}