wrapValue can destroy injected script.

R=dgozman@chromium.org

Bug: chromium:898062
Cq-Include-Trybots: luci.chromium.try:linux_chromium_headless_rel;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: I60c8d4a4b510b896a175346a3ba72ca8be43bca5
Reviewed-on: https://chromium-review.googlesource.com/c/1297290Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56919}