Revert of Replace LANGUAGE_END with LAST_LANGUAGE_MODE (patchset #1 id:1 of https://codereview.chromium.org/2257703003/ )

Reason for revert:
Needed to land revert https://codereview.chromium.org/2257133002/

Original issue's description:
> Replace LANGUAGE_END with LAST_LANGUAGE_MODE
>
> BUG=
>
> Committed: https://crrev.com/9324efca85710ebb14f21ef8476447e21cbe3f35
> Cr-Commit-Position: refs/heads/master@{#38707}

TBR=neis@chromium.org,marja@chromium.org,verwaest@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=

Review-Url: https://codereview.chromium.org/2259853002
Cr-Commit-Position: refs/heads/master@{#38713}