Rename translator_static to translator and use it everywhere.

BUG=angleproject:1596

Change-Id: I36c990d54979d2460b1513a65cca0b82f8d65c80
Reviewed-on: https://chromium-review.googlesource.com/406668Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Yuly Novikov <ynovikov@chromium.org>