Revert of [inspector] align console implementation with spec (patchset #2 id:20001 of https://chromiumcodereview.appspot.com/2428473003/ )

Reason for revert:
Breaks roll: https://build.chromium.org/p/tryserver.chromium.android/builders/linux_android_rel_ng/builds/164610

See https://chromiumcodereview.appspot.com/2434733002/ for more context

Original issue's description:
> [inspector] align console implementation with spec
>
> console should be non enumerable.
>
> BUG=chromium:656826
> R=dgozman@chromium.org

TBR=dgozman@chromium.org,kozyatinskiy@chromium.org
NOTRY=true
BUG=chromium:656826

Review-Url: https://chromiumcodereview.appspot.com/2435013002
Cr-Commit-Position: refs/heads/master@{#40464}