Migrate ExecuteScriptAndGetValue to new Value semantics.

BUG=646113, 940503

Change-Id: Ifbbb3c484e8f8d51cb20e742ea3d2c92ad7db689
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1513734
Reviewed-by: danakj <danakj@chromium.org>
Reviewed-by: Dmitry Titov <dimich@chromium.org>
Commit-Queue: Dmitry Titov <dimich@chromium.org>
Auto-Submit: Avi Drissman <avi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#642211}
13 files changed