Chrome OS: add oobe_welcome.js to closure compilation.

Should only add closure compilation target for oobe_welcome
and login_screen_behavior.
No functional changes.

Bug: 949409
Change-Id: Ib3e24737ace87b3617b6ffa10a4b887020ec3ce2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1552409
Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Commit-Queue: Alexander Alekseev <alemate@chromium.org>
Cr-Commit-Position: refs/heads/master@{#648465}
8 files changed