Revert of AppListController refactoring part 2: Ash's AppListShowerDelegate imlementation. (patchset #8 id:160001 of https://codereview.chromium.org/1856943003/ )

Reason for revert:
Trying revert again now that dependent patch was reverted.

Original issue's description:
> AppListController refactoring part 2: Ash's AppListShowerDelegate imlementation.
>
> Part 1 of the refactoring: https://crrev.com/1830293002
> Design doc: https://docs.google.com/document/d/1M9vqTTuprMssRXs8UIVaFjQUq3lUxSzwrWoPjPvca6Q/edit?ts=56d0e9f0#heading=h.b2znwtuxd2x2
>
> This CL adds ash::AppListShowerDelegate, which is the Ash implementation of
> app_list::AppListShowerDelegate. At this point it is unused - Ash is still using
> the old ash::AppListController class to control the app list.
>
> BUG=557408
>
> Committed: https://crrev.com/412803081c9d4f4321d267133512f45ce434fc10
> Cr-Commit-Position: refs/heads/master@{#386123}

TBR=sky@chromium.org,mgiuca@chromium.org,xiyuan@chromium.org,mfomitchev@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=557408

Review URL: https://codereview.chromium.org/1872033002

Cr-Commit-Position: refs/heads/master@{#386187}
8 files changed