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This is a reland of ddd08c52

Original change's description:
> OOBE: Arc-ToS Improvements
>
> Migrate ArcToSScreen to multistep behavior.
> Get rid of display: none; and display: block;
>
> Bug: 1156667
> Change-Id: I4c2fc425edd4883c5edfceb0a5a9f67a6227de7b
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2603744
> Commit-Queue: Ossama Mahmoud <osamafathy@google.com>
> Reviewed-by: Denis Kuznetsov [CET] <antrim@chromium.org>
> Reviewed-by: Roman Sorokin [CET] <rsorokin@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#844554}

Bug: 1156667
Change-Id: I53e9d533c9e3b7d5b5ba44dcf55997a3d9f6fab6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2637560Reviewed-by: Denis Kuznetsov [CET] <antrim@chromium.org>
Reviewed-by: Roman Sorokin [CET] <rsorokin@chromium.org>
Commit-Queue: Ossama Mahmoud <osamafathy@google.com>
Cr-Commit-Position: refs/heads/master@{#845620}