Revert "Reland: Make /deep/ as no-op and remove ::shadow in dynamic profile"

This reverts commit b160073dd51148f56b6586a9902b8a24674886c4.

Reason for revert: We've decided to delay the removal of /deep/ from M61 to M63.
See https://bugs.chromium.org/p/chromium/issues/detail?id=489954#c99 for details.

Original change's description:
> Reland: Make /deep/ as no-op and remove ::shadow in dynamic profile
> 
> Reland the CL [1], which was reverted at [2], since CrOS's OOBE issue was fixed.
> 
> - [1]: https://codereview.chromium.org/2778983006
> - [2]: https://codereview.chromium.org/2885153003
> 
> Bug: 489954,723259
> Change-Id: Ie162502385443a4e9a9cc80444c596458ad1e100
> Reviewed-on: https://chromium-review.googlesource.com/575322
> Reviewed-by: Takayoshi Kochi <kochi@chromium.org>
> Commit-Queue: Hayato Ito <hayato@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#487745}

TBR=kochi@chromium.org,hayato@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 489954, 723259
Change-Id: I1b58db5bc2f3268f16b832214b87f1d77ada38ee
Reviewed-on: https://chromium-review.googlesource.com/609602
Reviewed-by: Hayato Ito <hayato@chromium.org>
Reviewed-by: Takayoshi Kochi <kochi@chromium.org>
Commit-Queue: Hayato Ito <hayato@chromium.org>
Cr-Commit-Position: refs/heads/master@{#493331}
12 files changed