Revert of [debugger] debug-evaluate should not not modify local values. (patchset #2 id:20001 of https://codereview.chromium.org/1513183003/ )

Reason for revert:
[Sheriff] Layout test changes.

Original issue's description:
> [debugger] debug-evaluate should not not modify local values.
>
> Debug evaluate no longer writes back changes to the replicated
> context chain to the original after execution. Changes to the
> global object or script contexts still stick. Calling functions
> that bind to the original context chain also have their expected
> side effects.
>
> As far as I can tell, DevTools is not interested in modifying
> local variable values. Modifying global variable values still
> works as expected. However, I have not yet removed the old
> implementation, but merely keep it behind a flag.
>
> R=mstarzinger@chromium.org, rossberg@chromium.org
>
> Committed: https://crrev.com/92caa9b85eefffbef51c67428397951bd2e2c330
> Cr-Commit-Position: refs/heads/master@{#32841}

TBR=mstarzinger@chromium.org,rossberg@chromium.org,yangguo@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/1526553003

Cr-Commit-Position: refs/heads/master@{#32845}